So, I got one yesterday and have a real 303. I’ve tried it extensively before purchase.
It's too early for me to do a proper review but I can give you some insights.
The sequencer is awesome. It's a real improvement compared to the real one. Dead easy to use.
I don't know much about the latest Sokos O.S. on Xoxbox so I can't compare here.
When controlled externally, key tracking is fine. If need be, the TT can be use as a midi/cv converter.
Sound wise, it does the job pretty well but the 303 wins.
Still, in many settings, I can't tell the difference. I'm impressed. Great clone.
However, I found two noticeable weak points imho. It's not perfect.
First, the high could be a little harsh when the resonance is fully cranked.
My guess is that real Roland diode filters just can’t be replace.
Second, the accent is sometimes less cutting than the one of a real 303.
All in one, the 303 is a bit more “liquid” for lack of a better word.
Those slight differences are no deal breaker as the 303 mojo is definitely in there. Same territory.
IMHO, it won’t make you sell your 303 if you have one… But any 303 owner would be pleased with one.