my brother upgraded from a geforce 2mx 64mb to a geforce4 mx 440. Even though there was a performance increase, it coudn't match my ti200 even tough we have very much the same setup.
He just got a ti4600 2 weeks ago and booooy its a night/day difference.
I underclocked it to ti4200 speeds and saw that performance was still pretty fast. So I'm getting a ti4200 myself and overclock it to at least ti4400 levels.
Sometimes I hate being right everytime.