I use them all the time, almost to the point where I barely take my full length ones out anymore. Once you get used to the technique, slippage is minimal and the weight advantage is great, especially in the spring with water gain. They are perfect for rolling terrain, where you don't want to remove skins every time you hit the flats/downhills. I also love them for once you are up on a ridgeline and are moving laterally along the ridge. The tips & tails of the ski still have enough exposed edge where your ski doesn't wash out like full skins do (very unerving on a steep angle). I can comfortably climb up to 20 deg slopes. If you use a specialized technique of minimum strides and maximum underfoot pressure, you can climb up to about 25 degrees.
Well worth the purchase.