I have a WM Antelope with Gore Windstopper. I bought it used so I didn't have a lot choice with the Windstopper. If I were to buy another WM bag I will get one with Microfiber. For me the Microfiber is water resistant enough and I feel Windstopper is not worth the extra weight.
I don't have a Kifaru slick bag but I have a Mountain Hardwear Phantom 0 and a Marmot Lithium (both 0 degree bags) and I would say the Antelope has more loft than either one of the them. I've been warm in the Antelope down to -6 degrees.
I'm a side sleeper and I roll around a lot. I prefer a bag with a hood for when its cold. When its warmer I don't zip my bag up all the way and have even laid my head on top of the hood instead of inside of it. I've never cursed my bag because it had a hood.
I would lean towards getting 0-5 degree bag versus a 15-25 but I'm a cold sleeper. There have been more times where I was cold wishing my bag was warmer than being too warm and wishing my bag was cooler.
