Take what you see here with a grain of salt. Probably many corrections to come.
I was a little afraid in my initial post that I was going a bit much into lecture mode. And it's important not to lecture, because I am certainly not an expert, just a guy with a timegrapher who likes accurate movements and maybe spends too much time reading about them.
Basically I see a ladder in commodity movements, with the steps mostly arranged by the degree of adjustment and the allowable variance of the given movements (and the higher rungs being so placed largely because of engineering decisions). ETA 28xx are kind of funny since they occupy several non-consecutive rungs of that ladder. It's also true that some examples from any particular "rung" might outperform watches from a higher rung, but I think of them as rungs as a general rule. (For instance, I have one NH36A that the timegrapher tells me is more accurate than several Miyota 9-series and 2824-2 family movements I've tested. Yet every other 7s/4R/NH3xx I've tested has been a medioce performer at best, and some downright awful. So I think I got lucky with that lone example.)
Maybe it's more a floor, ceiling, and most likely result thing. For instance, I'm pretty convinced that the base grade 2824-2 has a higher floor in terms of its worst performance than the Miyota 9-series, and this is born out in in published detailed specs and also in timegrapher testing by many people. It may also be true that the base grade 2824-2 has a higher ceiling in terms of the best performing movements, but I'm far less certain of that. What I am pretty sure of is that the average 9-series is going to outperform the average base grade 2824-2 most of the time. Plus it's cheaper. Plus it's thinner. Plus its handwinding mechanism is more robust. Plus it seems - anecdotally so far - to hold up longer without service. Plus I find the gyroscopic whir of a unidirectional winder rather charming. So I'm a big fan of the 9-series.
Elabore grade is maybe hazier. I've only tested one so far, and it ran right in line with a pack of base grades. Looking at the specs from both ETA and Sellita, there really doesn't seem to be much between base and elabore; they are adjusted in 3 positions instead of 2, and the allowable variance is slightly smaller, but not enough to be easily noticeable without a large population of watches. The parts are basically the same, the difference is mostly in finishing and in slightly tighter specs. So again, I'd pick the 9-series nearly every time; though I think the best elabores are probably better than the best 9-series, I think they're probably still loosely speced enough not to be worth the cost and comparative fragility vs. the Miyota.
Where we really get cooking are in top and chronometer grades. There are no difference in parts between the two as I understand it, it's simply that the latter undergo a bit more testing, then are sent off to COSC for very thorough testing and certification. No one wants to pay for COSC testing of a movement likely to fail, so it's reasonable to assume these two grades are very close together in practice, likely identical. And when we get to the difference from base and elabore grades, we see marked differences: they are adjusted in five positions vs. 2 for base and 3 for elabore, the allowable deviations are tighter still, the maximum variance is tighter, and so is the allowable isochronism. The balance wheels and hairsprings are of different material than the base and elabore grades, the anti-shock mechanism on the balance is different. They truly are superior movements, and I would leap for one as an upgrade any time.
Higher up from the rather basic 282x/283x series, we deal with the 289x movements, and those are a whole 'nuther kettle of fish. The top and chronometer grade 282x/283x are probably better than the base model 289x, but the top and chronometer grade 289x are very special movements. I get giddy when I see them placed in affordable watches.
Re. Sellita vs. ETA, I'd suspect from others' anecdotal evidence that the ETAs might run slightly better, but at least in the 2824-clones, the Sellita has a longer power reserve, so it's kind of a toss-up, and I don't really care which one is in my watch.
The funny one of the 282x clones is STP. The 1-11 is specced in adjustment, positional variance, and max deviations in line with a top-grade ETA or Sellita, with isochronism only at the level of the elabore grades. That's still a heck of a movement if it meets those specs. But do they? I don't know. I know there were a lot of teething problems with these movements a few years ago, but I've not heard much lately. They might be the dark horse here, the true best bargain movements. The STP 3-13 is pretty much the same thing but with a swan-neck regulator for better fine adjustment. I have no idea of the cost difference of the 3-13 over the 1-11, nor as above if it meets it's specs, but it sure is an intriguing one. Additional info from the other thread: AndroidIsAwesome confirms that STP reliability issues are real and on-going, so these might not be such a deal after all.
So to wrap up my thoughts in this somewhat offtopic post that ended up way longer than I'd planned (and as warned above is not written by an expert ), here are the rungs of commodity movements - with all the above caveats, plus admission that I don't have data on a lot of these and may be completely offbase (especially, I'll add in this repost, when it comes to the myriad Chinese movements usually offered in a biwildering variety of different grades) - as I see them, in reverse order:
- Ultra-cheap Chinese of domestic design (the sort like badly adapted automatic Tongjis in $15 watches)
- Vostok (not sure how available they are, but I know a few other brands in the past used them - they are said to be robust and long-lived, but they're usually awful runners)
- Low-end Chinese domestic designs of mass production but with okay QC
- Chinese Miyota 8xxx clones (though they do usually hack)
- base grades of Chinese ETA clones and the better of their mass produced domestics (ST25, etc.)
- Seiko 7s
- Miyota 8xxx - the handwinding is a nice upgrade from the 7s that to me more than offsets the stuttering seconds, and some of the newer ones hack too.
- Seiko 4R/NH3x
- base grade 2824/SW200 families - high grades of Chinese clones and some of their domestic designs are probably about here too
- elabore grade 2824/SW200 families - maybe the best grades of Chinese commodity movements belong here, including the best clones
- Miyota 9xxx (may or may not be better than elabore grade above, but generally a better compromise and clearly better than base)
- I originally had the STP 1-11 about here with the caveat that was only if it met its specs, but in light of AndroidIsAwesome's experience, it probably belongs a few rungs down
- base grade 289x/SW300 families (These probably don't exist. See posts below.)
- elabore grade 289x/SW300 families
- I originally had the STP 3-13 about here with the caveat that was only if it met its specs, but in light of AndroidIsAwesome's experience, it probably belongs a few rungs down
- top grade 2824/SW200 families - often the best accuracy/price combination in affordable watches, but sadly underused
- chronometer 2824/SW200 families - the best movements often seen under $1k - Chris Ward uses these a lot, as do a few others.
- top grade 289x/SW300 families - best movements I sometimes see in sub $1k watches
- chronometer 289x/SW300 families - sometimes seen under $1.5k. Not sure if or how many of these I've seen under $1k, but they would be a heck of a buy.