I thought I'd share my recent experience with Castle customer service.
I had the misfortune of smoking a fairly new MM2 ESC, the web site return process was very user friendly.
I sent my ESC in for evaluation, it got there on the 24th according to USPS tracking.
I emailed them on the 25th just to see what I could expect. I got an answer back the next day informing me that my ESC was covered by warranty and that the replacement would be processed today.
I'd say that's a pretty good experience.

I won't run anything but Castle Creations products in anything I own.