a head angle of 74deg on its own shouldn't make a bike that twitchy. Must've been a few other factors affecting weight distribution or the balance of the bike (or both).

If you take two bikes set up the same except for HTA (say one with 72HTA and the other with 74HTA) then with all other things being equal you should only really notice a difference at high speeds (typically entering corners on fast downhill runs). The bike with 72HTA will be marginally 'lazier', and that's about it.