Yesterday I was jumping back and forth from my Pro to my Viper as my son was riding the other one, and a couple things stood out to me. First, I noticed the weight alot more then I would have like to.. But I could not believe how much better the ride was on the Viper with the added weight, and perhaps much better shocks. From the road bumps, to bumps in the snow, the sled took the hits far better then the Pro did, as the Pro got tossed around in the same scenario. Better shocks on the Pro could help that scenario I am sure, but doubt it would fix it all.
Other thing to note, when the sleds dart on the trail, the Viper and its added weight is much more difficult to pull the skis out of the tracks.
So that being said, as much as I love my Viper, if it come down to arm strength via injury or any other reason, I would take the easiest sled I could find to turn, pull over etc.. Lighter would be my vote. But it would also be a sled with a straight steering post...