The Halo Too was designed to be the cheapest Halo loader available, until the prices dropped on all the others. It's got a sound activated board, and a static drive cone without a tension spring. Of all the Halos, it will probably be the toughest on paint.
The V35 uses eyes to determine whether or not it should load. If it jams, the board starts flashing at you and won't load until you turn it off, then back on, which I don't like.
Between the two of them, I'd go with the V35, simply because it's the more advanced loader, and will handle paint better.
Paintballing for more then 5 years