No concerns whatsoever ever. If I have the option for an aluminum shaft over a steel shaft I’ll take it. I’ve used a few crown Victoria aluminum drive shafts in projects and they work great and are considerably lighter.
Some of the videos I've seen showed no performance difference. There may have been a very slight performance gain in first '60 ft. With a very slight drop-off on big end. Not enough to draw any conclusions.
It's not as much about performance (although there is a gain there too) but you'll see improved suspension compliance through reduced unsprung mass, and a reduced sensitivity to imbalance since there's less mass spinning underneath.
It benefits several systems at once, including less stress on the tail shaft housing and bearing, and better overall engine acceleration
A lighter driveshaft should not affect big end performance one bit.
