I bought my runner with that kit. I ditched the front spacers as of last week to go with Bilstein c/o's. But I still have the rear installed. Over all RC really isn't too horrible of a company. They make some decent jeep lifts. But as for this kit, the spacers up front suck dog balls, because well...they're spacers. They add stress to factory suspension that it wasn't designed for.
As for the rear. It's not terrible. It actually flexes decently, but the ride is definitely something to be questioned. You definitely will not retain a "factory" like ride with them. They're quite harsh. Once I installed my from c/o's the difference was literally night and day between the two quality wise. (I know comparing front to rears is a little different) but still I would imagine OME's, ToyTecs or something would definitely ride better.
If looks are all you're going for, then sure why not. It's cheap. But if you want something that will ride decent and perform well and last, save your pennies.
Check my build thread for some pictures of that kit installed with 265/70's and 285/75's
http://www.toyota-4runner.org/3rd-gen-t4rs/159925-tank_7s-build.html