I prefer '07 mainly because it was the first year in which the canister sets weren't all clones of one another. Get one Toa Inika and one Piraka, and you pretty much have them all as far as build is concerned. Even the parts-pack Voyatoran had more variety in their builds than the big boys in '06. In 2007, by contrast, all the Barraki had different builds, and apart from Kalmah and Carapar, those builds were very unique and interesting. The Toa Mahri also used a variety of different builds, and even though that meant the gap between the best and worst Toa Mahri set was much larger than that between the best and worst of any previous toa team, I still think the variety was a good thing.