I've heard good things about Asus and Acer, but my *nix buddies seem to like Lenovo better for driver support. I don't think the brands mean much; it's the specific models and their technical specifications that are worth investigating.
It is solidly built, very easy to pack, and the keyboard is great for an ultrabook. The trackpad is also good.
I also have a Yoga 2 Pro, which was great value for money and pretty lovely, but I wouldn't want to type on it all day.
In my case first the RAM stick died, then the LCD inverter, then the WiFi and then the HDD. All in a scope of one week, three weeks after the end of the warranty. It was spectacular.
Within each brand, there seems to be a lot of variability in quality from model to model.
I have on occassion bought Acer PCs for non-devs at the office, and have regretted it every time. Sure they are cheap, but they also break down very fast and/or have lousy driver support, its just not worth the hassle. I still remember the stationary Acer PC I buy for one of our salesguys. Everytime he went above 50% CPU usage it sounded like a vacuum cleaner, and could be heard from the hallways.