As someone who has watched silents with live music I can attest that the experience can be great (or not, depends a lot on musician(s) and music) and you should definitely go for it when given opportunity. However, I completely disagree with the idea that movie will somehow be sullied or even ruined if you watch it first on your own TV.

Basically, yes. There's a finite number of preserved silents and the subset that even gets a screening from time to time is even lower. Paradoxically, the less opportunities you have for proper watching, the more likely it is that you will get one that you have already spoiled on the small screen, because the selection criteria are the same.