I think with 3+ players I'd be fine with either side, but in my 2 player games I'd rather enforce using side B. It could have been attributable to the library, training grounds, and guild's presence in the room set up, but the last 2 player session I was engaged in turned into a 5+ spells/player MAD arms race. I'm sure some folks might enjoy a mega-magic game, but that much research flying around bogged the game too much for me.
Playing with a new player, I nixed including the Techno's. Side B leads to less complex board states, but adds hidden information. Wasn't sure which would be more confusing, so I just nixxed.
Indeed, IMO they were the correct choice for the expansion set mages.