Re: WHAT'S BETTER: Tube amp reverb or a boss pedals reverb?
In general, amp reverb will be better sounding, certainly more natural.
Pedals are often much more versatile than amp reverb though - they often have diferent types of reverb (room, hall, spring etc), ability to control reverb time, and have much greater range. Also, amp reverb is quite often not footswitchable. And as has been said, it depend very much on the amp.