I pretty much never buy anything until it’s been out for a while, probably for similar reasons to you but I’ve been really impressed by the stability and reliability of the Syntakt so far (I ordered on day one, had it about a month now).
There’s a few bugs, but a lot of them have already been dealt with by the update and, to be fair, I’ve only experienced a couple of bugs, neither of which have affected my ability to use it or interrupted playback. I’d say so far it’s been a lot more reliable than the Digitone and Digitakt I’ve owned previously (not that they were unreliable, but they weren’t as stable as my Syntakt has been so far).
Obviously none of us know about long term reliabity, but that’s why there’s a 3 year warranty. I’ve sent stuff back to Sweden for repairs from here in the UK before, it’s really easy.