More feedback ...
Marius ...
I am currently playing with the DNX 10 mid and have posted comments on this one elsewhere. I have tried all three racquets (and been dedicated to the Gen 2) that you are looking at and will try and restrict my comments to these.
First the Tour 10 Gen 2 ... This one has been my main stick over a two year period. It is very arm-friendly and I have had no problems with my elbow or shoulder. For such a flexy racquet it delivers amazing spin and power. The racquet should work for your friend if he has early preparation, a fast, complete swing and maintains good footwork. I can have problems with this one if I am tired and get lazy ... other than that, this racquet plays like a dream!
The DNX 10 MP ... I played with this one on a demo program (three outings) ... I hit some good shots with this one but primarily found that the throat area (and perhaps the dnx hoop area) felt a bit stiff ... slightly cast iron frying pan like. My serving and ground strokes were felt good but not great. It could be that I didn't give this one a lengthy enough try ... but this one played heavy as opposed to the the Gen 2 and DNX 10 mid that were instant winners with me.
And, the Tour 10 V-Engine MP ... I tried this one on four outings during my demo duty. I liked the way it plays and it has excellent pop when you want it. However, my favorite two racquets are slightly easier to manuever (for volleys, etc) and they both have what I have been calling the super-sweet spot. The feel of hitting a near perfect shot, hitting the sweet spot and seeing the result is like no others that I have tried. I did like the play with the v-engine mid plus (I also spent alot of more than a year playing with the Tour 8 V-Engine) but it didn't have all the attributes I looked for, including the super sweet spot. Again, I might have come up with a different conclusion if I had tried this one some more (I did bring it home on two occaisions for a total of four outings). Nice racquet but not a perfect match for my game.
And, for what it is worth, I use the MFiL 300 as my second backup and find that this one is slightly lighter (I think the swing weight is less as well) than my favored Volkls. I find that this racquet is also arm-friendly (unlike what your friend found) and a good choice when I am tired and not preparing early enough, not finishing my swings properly or being slightly lazy with my footwork. I try to not get to this point but sometimes it just happens.
Hope this helps.
TourTenor