They're both much the same to be honest. I've bought and used products from both company's and never had any problems with either.

Out of personal preference and given the choice, I'd go for Farallon. Probably for the simple reason you tend to stick with what you know best and I've used a number of Farallon products in the past (more than Asanté) and have always been happy with their reliability, ease of installation and use.

I don't think you'll go wrong with either.