hi mango,
i came off the b737 to the b777 about a year ago and i can tell you the b737 rides turb much better than the b777. i believe it's got more to do with the material the wings are build with. i recall the ride on the b744 was alot like the b737 probably better, maybe due to the wings flexibility? i have heard horror stories from a330/a340 guys regarding its ride thru turb. i think with the more composite material there is in the wings the less flexible it becomes...