I already have RS250 . I am happy with it, as I watch lots of video music, not just audio files, and it definitely sounds better than my Mac Mini M1. However, when playing video files from its own SSD some files stutter , whichs ruin the experience (it appears that it is ‘thinking’ about something as the round little circle in the center appears). Amazingly, this stutter does not happen when RS250 is playing exactly the same file from my home network, over the Ethernet network.
My question is , what is the difference between the original RS250 and the new RS250A , as the specs appear very similar ? Here in Australia the prices now between these two units are quite different (AUD3000 vs AUD4200)!
They improved the entire Digital section and Output Stage. Along with that,they improved the DAC big-time as well as the OP AMPS. I have an RS-250, which I purchased about 45 days before the RS-250A came out, so I am very envious…As some of the upgrades are PCM up to 32/768 and DSD up to 512…unless you are a Classical Music junkie, there is no music you can get that uses this resolution. As far as the OP AMPs, I never opened my case, but it usually is super-easy to upgrade OP-AMPs. Just call BURSON, who is the premier consumer-based OP-AMP manufacturer and seller. They pick up the phone,and will answer every question about OP-AMP upgrades. They are Plug-In and take about 2 minutes to install…
…but…I will bet you a steak dinner, that if we had a blind-fold test, if you are over 50 yrs old, you could never tell the difference,between the two boxes. I was in the Concert Biz in college many,many yrs ago… I know my ears can tell…I will give you a MUCH better upgrade…No matter which speakers you use…purchase a SUPER-TWEETER. They cost between $300-$2500 USD…That upper end that we lose as we age, is clearly projected seamlessly with your other drivers. I have FYNE, Tannoy and Paradigm speakers…and my purchase of Aperion Super-Tweeter was the best $450. I have ever spent. Good luck and feel free to ask other questions…SIEGES / New Jersey USA 
The rs250a has a better dac output stage and clock. This makes an already decent dac a very good dac. And it comes in black.
Other than that it’s the same.
I wouldn’t upgrade for just that, but I have an external R2R dac. I do use the Rose internal quite often though. Because my dac doesn’t have a remote and for most purposes the internal dac is quite OK. For the price difference you can do a lot of other things.
You could upgrade the opamps. I just rejected an offer from John at Burson to try out his discrete opamps. I didn’t think of the RS250. But unlike most of my gear which is all modified (heavily) I don’t want to open up the Rose. It does everything I want so I would rather keep it original. From my other projects I can tell you however that opamps can make a lot of difference! I also know that clock upgrades are significant too.
But your problem is video playback. I think it has to do with the performance of your SSD. Some cashing problem. Mine is good but still on 2160p I notice a little more choppyness. I can also access my Rose as a network share and play from my android TV. That sometimes solves problems with subtitles and is a little more fluid. No problems with 1080p.
What sieges says about supertweeters is also valid. I don’t need them because I severely dislike dometweeters. I only use AMT and ribbons. For exactly that reason. Same goes for a good fast subwoofer. It adds a lot to the sense of ‘being there’.
The speakers are the most obvious for changes in sound, but without a good source it’s GIGO (garbage in, garbage out). Dacs really do make a difference. And over the last ten years there has been a lot of improvement.
But original RS250 does 32/768 and DSD512 just as well.
You probably could measure 250A as producing somewhat more accurate output, but whether it is actually audible…
Super-tweeter would be interesting to try – it is highly unlikely that anyone over 40 could exactly hear it but apparently it might actually have something perceivable to it…
I’m 60 and I assure you , I can clearly hear the difference with my Aperion Ribbon Super Tweeters. We cant bet, but to say you can hear the difference between 24/192 and 32/768 is not honest…If there IS a difference, it would be so small, that the price spent makes no sense. There are other ways to upgrade your gear, with better results than to purchase the RS-250A. The biggest reason may be that if we sell our RS-250 boxes, the used market is well under $2k…and it is stupid to get rid of the RS250 at the prices people are paying for used IFi rose DACs
Sieges
Honestly, I doubt that even 24/96 is audibly distinguishable from 32/768, when most people can’t tell MP3 from Red Book.
Those tweeters look interesting; if anything they actually do perform the claimed function, which is already more than can be said about most high-end audiophile products 
I think the 250 is perfectly fine, I m not going to lose any sleep over measuring slightly better but well beyond anything that can be heard.