I recently lost a game when I did my best to get champion asap, using Changeling to get pages that turns into warior (side note : treasure hunter + changeling is really good). Warrior was the only draw, so it was pretty important.
Thing is, my opponent (lower level than me) played a more conventional Big Money thing, buying provinces early, one province per turn, and getting several heroes.
At the last 3 turns of the game, I had a very good deck that played a bunch of warriors, trashing his remaining silvers. The problem is that my opponent was flooding his deck with gold from his heroes, so trashing silvers eventually helped him. Even when attacking him with legionnary, he kept having 3 gold hand, and bought provinces while I was desesperately buying duchies
yes, because I forgot to say the major thing here : there were no +buy, so having hand that produce $16+ didn't help.
After the game I realized I could have Stonemason Gold into double duchies, but didn't think about that during the game.
So, in this particular case, Champion was not so great, though if I played more carefully and thought about the stonemason thing, I could have won rather easily.