We HAD asus ultrabooks when I started at my new job...I could not get rid of them fast enough. J.U.N.K. If you have to get new, get dell. Just get the DELL warranty. You can get next business day on site repair on them so your kids aren't stuck without them for long. Lenovo has a couple upper end models that are really nice...but pricey. The X1 series is ~$1600
My experience with Dell has been similar to yours with ASUS. I won't even look at Dell for any new laptop purchase. Too much of their base hardware is tied up in proprietary cards that can't easily be changed. My personal laptop is the near-high-end N-series ASUS...complete with an NVIDIA GeoForce GT graphics card right from the factory. Running 3D BIM software makes me really picky about the hardware, especially graphics cards. But I digress...
I also have a Toshiba that belongs to my daughter...I've had no trouble with it whatsoever either. I gave less that $400 for it, and it does everything my 15YO daughter needs and then some.