I got a 1/2" extendable ratchet from HF a few years ago and it's not bad at all. Good for junkyard runs, in that it fits in my small toolbox. Also, after you crack something loose, you can slide it back to its shortest length and move more quickly on the loosening.
HF's smaller version, 1/4" dr. on one side of the head and 3/8" dr. on the other, that struck me as awkward and a potential problem.
If you're looking for quality (and to spend money) somebody just a few days ago posted some FACOM extendable ratchets here:
Haha. I decided to use an adapter with my 1/2 gun after lunch ended up snapping both adapters on a very stuck lug nut. Was expecting the socket to go before the adapters. I didn’t even try the 3/8 because if the half couldn’t get it then I knew the 3/8 wouldn’t. And I had to use the chrome...
www.garagejournal.com