I’ve heard from people who’ve had good experiences, but — honestly — it makes me very nervous. There are too many potential problem points. In a high-latency scenario, the constant server communication could make the UI lag. Keeping a per-user bundle of state on the server is never a good look, because who knows at what point scalability fails (usually the worst possible point) or you’re prevented from moving to a different type of hosting environment. But the big problem is that these issues, if they are indeed problems, are unlikely to appear until your application is deployed and growing.