Yep ... 'depends' ... + you've really answered your own question when it comes to themes and addons.
Having said that, however, if the site is installed with git and you follow a wise and 'good' site backup practice ... one should always research an addon and/or a theme anyway prior to attempting to install. So if you are a 'gotta have' theme or addon person, then they determine when you jump.
But ... I'll bite ... I wouldn't recommend a x.x.0 of any major release as that makes you an 'omicron tester' - wait til x.x.2 or .3 for the 'dust to settle'. Long Term Support versions ... get to them as soon as you can so you can enjoy (or ignore) the 'nags' (notifications about new version available). Easy to do with git.
Having said that however, versioning to change in near future ... when what would have been 4.0 is released it will be 400 ... think that will be interesting to see just how confusing that will be.
Also ... what you have now will become production you say ... Just before making it 'public', advise cloning it to a dev site and tinker/play there all you like considering you said you weren't worried about 'infrastructure'.
Actually, the stability of 'STABLE' has a alot to do with server admin him/herself ... if they are 'STABLE', site usually is!
My 2 'sense' ...
'SoS', Ken