There's nothing wrong with the traditional "wet" bearings, that float on oil, personal choice, if you want to cut down lag to a minimum etc then go roller bearing, esp as there is not such a drastic price difference now.
Personally I think the roller(ball) bearing ones spoil the character of the cossie but others like them better.
I have the std wet floating bearing on my T3-34, with 360 degree thrust, and step gap seal.
tabetha