Sigma is pretty good. I had a twist-lock mount break on me a couple of years ago. I sent them an email and they sent me a new one. Didn't even want me to return the broken one. Their 2006 and 2009 model computers (*06 and *09 designations) don't reset at 10 hours, either. You can actually use a Sigma for the entire Paris-Brest-Paris and get your totals (while you're moving, anyway).

Luis