Simple truths about driveshafts.
1)Shorter ones are simple to balance.
2)Rubber isolated center/carriers make most setups less vibration prone.
3)The more pieces you have, the more it weighs.(All things being equal of course.)
4)One piece shafts are lighter just for the reduction in cast yokes, U-Joints and other stuff you don't need to duplicate, but they are very sensitive to vibration as they get longer. (Just from flex, at speed, they will resonate and create vibration in some cases.)
There are options to reduce vibration while not adding much weight.
Carbon fiber wraps, or construction.
Alluminum for light weight.
I went with a carbon fiber tube and had no problems for years, but found out later that it was built with a damaged U-joint cap, and as it wore out, created some slack/vibration. The repaired driveshaft has vibration now, and all the local driveline shops don't have machines that can balance over about 2500rpm. (Sucks since our shafts turn to 6000+ in the higher gears at high speed.) The only thing that was changed is welding up the yoke plug that was leaking oil. I need to grind that weld down flush everywhere, and see if that improves the balance.
Another nice deal of going with the larger more expensive driveshafts is better quality U-joints. They don't get flexed much in the Supra, so even the stockers hold up, but the stockers are a very small joint design compared to some others out there. (On my setup, it's a larger U-joint that fits the stock transmisison yoke, and then a larger Spicer one at the rear.) The best setup would be one that has a new transmission yoke that accepts a larger joint with the same larger one in the rear too.
Only driveshafts I've seen torn up were stockers being subjected to 500+hp and one CF unit that Duane turned into a dust mop down in Vegas. (I have that same shaft, so I inspected it, and found the lose joint etc.)
