They're quite good, I've been using the older Ansmann version for the last 4 years with no problem. The other benefit is you can buy these super cheap receivers if you want to add more vehicles as it's a copy of the Absima receiver & will bind without a problem:
http://www.hobbyking.com/hobbyking/s...arehouse_.html
I've been using the HK 'clones' for years too & haven't had a failure yet.