There are going to be pros and cons to every type of stringer. I find the two-cup more difficult to use than the cup-pad type, but that's just me. Somebody earlier mentioned using 2 feet if necessary on the cup-pad type. To my way of thinking, that is the only right way to use it. By having your feet spread and the string its original full length, the downward pressure on the pad is almost straight down, so it doesn't tend to slide back toward the riser.
I always string my recurves using a stringer, but use push-pull for my longbows just because I can. For what it's worth, I just tried stringing my 68" Two Tracks Echo with the cup-pad type stringer and it worked great. I'll grant you it's a light bow (maybe 60% of the weight you're talking Bud), but again, the pressure is pretty much straight down on the upper (and lower) limb, so there is no tendency to slip.