I don't have up-to-date information but last time I looked my impression was that you need to look down to the level of specific models - looking for reliability at a brand level is just going to average out a lot of highs & lows and not help you much.
The anecdotal information that makes it to the internet is the combination of brand/model reliability and how good the local installer is, which adds even more noise.
At the risk of getting too depressing, the heart of modern American business practice seems to be taking well-regarded brands, building them really cheaply (typically outsourcing the mfg), and selling a lot of units at high margins before the public figures out what happened.
Back to (hopefully) useful info, last time I was looking for HVAC equipment I got a lot of useful info from the forums where installers talk to each other, eg:
http://hvac-talk.com/vbb/forumdisplay.php?1122-Tech-to-Tech-Chat-Residential
