Your front CV's will probably wear out more quickly than they otherwise would from the added angle. The actual driveshaft in the front is unaffected but the rear runs at a little more angle as well. That said the dealership I bought my quad from installed mine for me before I brought it home and I questioned them beforehand on warranty. They flat out told me that they would still warrant my suspension and or driveline with no issue. Okay. Truthfully for me however, if the stock CV's bite the dust I will replace them myself with stronger parts anyways. That I may actually break down and add the Detroit locker in the front over the winter which I am sure will just help them along their way.
I like the 2" lift on my machine. I have a buddy of mine with another 420 as well as a 500 Rincon, both with lifts. The Rincon has had the front CV's replaced but I believe that was even before he lifted it, lol. The 420 has had the lift for a year and half of hard riding and it's still fine. The added clearance for the center skid plates and front diff is nice. I ride in a lot of muskeg and big mud holes. And we all ride hard, so we actually go through the holes and not drive through the trees to attempt to go around them, lol. I didn't want bigger rubber without being able to compensate gear wise ( although I can do the gear reduction I guess) and right now the power is good( pipe and PC3 made a nice difference). I probably will go with Maxxis Zilla 26's next go around as my friends 420 has them and his does better than my Mudlites can( he rode mine and vice versa, the tire is better to climb sand and it does better in the mud, imo).
That and I know guys say they are tippy but that is flat out untrue. We are talking 2" here. I am just as confident in cornering this machine now as I did riding my friends 420 when it was stock. He feels the same way and had a year and half of time in both forms ( lifted versus stock) to figure it out.
So in the end, if you are only concerned about the longevity of the CV's, leave it stock.