3U is lighter than 2U but also more fragile than 2U. 2U can hold higher tension than 3U. I can't tell you which is better as it is all depend on your playing style and so. I have a 3U MP77 and I like it as its weight.
I have a 3U MP77, and I am very very comfortable with it. I have never used a 2U Mp77 before so I cannot comment on it. the 3U is light, yet is powerful for smashes. best is if you go to shop and try both out. Feel both and go with what you like. Ultimately its all about what you get used to
G'day, I have used both 2U & 3U version extensively and here are my experience with both: 2U - more powerful, more stable, sturdier, heavier, can hold much higher string tension, easier to play singles with, and survives multiple racket clash. 3U - whippier, faster to move around, lighter, better for net shots, great for double. Not so great in withstanding clashes. But ideal for female players as 2U version is quite hefty..... Hope this can be some sort of help
