Am now using it for warm up...and as training racquet.
Probably should have gotten the 4U version...but hey lesson learnt.
4U should retain most of the head heavy balance and stiffness but with easier or more agile (wrist/finger) handling.
With a heavy 3U version, it's harder to do those reflex based half-court drive shots seen in doubles. Here the professionals exchanging drives to force the others to lift, to kill the shuttle. e.g.