Can anyone who has used both chime in with their experiences? How did they find and any particular preference? I play mainly doubles so was veering towards the 4U version, but that depends on how fast the 3U swings in comparison to my 3U MX80. Any thoughts would be welcome. I guess ultimately I'd like to know how much power you lose with the 4U VT80 and how much speed you gain over the 3U. Also, will the 4U VT80 still have more power than a 3U MX80? Thanks.