Biased opinion here(you don't say?!?!)LOL
The needle bearings are a much more precise item, the interferance between the bearings and the shaft is held to within .0005 of an inch.
The needle bearings are closly related to the wheel bearings inside your front hubs (and these sure take a beating, wouldn't you say?
)
Bronze bushings are closer related to the bearings
inside your engine. Sure they stand up to tremendouse forces, but you also have to remember that the oil is constantanly being pumped in between to create a layer to prevent damage. Yes, the bronze bushings do have grease fittings, but after a few cycles up and down the grease will no longer be able to protect the mating surfaces between the bronze and the metal sleeve (unless you had means to constantly supply new grease)
The needle bearings have an initial higher up front price, but in the event any of the bearings need to be replaced 5 years down the road, the bearings can be bought for a fraction of the kit price (~$15 bucks per housing).....the main cost in the kits is the housing that the main bearing fits into (made from Seamless tubing to prevent spliting) and the sleeves (made from a solid rod of 52100 steel, then it is hardened and centerless ground. How hard?, about the same hardness as the big ball bearings inside a CV joint)
Front and rear kits are in stock...(I'm out of town from tommorow until next Thrusday)