From what I've seen, the coil overs provide a very cush ride. I thought my duals were pretty cush but have ridden in a similar truck with the coil overs and was very impressed. May have to do with who does the install, professional versus handyman.
As for how my truck rides, It rides much better then the stock truck almost like a nice car. Very comfortable on long trips across these crappy roads. And it rides incredible on offroad trails.
What do you plan to use the truck for? Depending on the use will determine if 10in is too much. I drive my truck just about everyday and us it for camping, bass fishing, dirt biking (quads are for those who can't ride), mountain biking, hauling a camper, etc.. I couldn't do a 10in lift as it would be too high for unloading and loading what I use it for. As it is, I have to have longer ramps for loading and unloading my bikes. The tailgate step definitely is a must for a lifted truck.