Very true. And even in long, professional play its not uncommon to see GM's play highly tactical, but unsound openings if they think the other player doesn't k

Very true. And even in long, professional play its not uncommon to see GM's play highly tactical, but unsound openings if they think the other player doesn't know how to beat it. E.g. I saw Nakamura play the Kings Gambit once against somebody sub-2000 in a professional tournament once (not blitz, full regular timed game).