I've been using swsusp2 for several months now on a Gentoo-based system running kernel 2.6.13 without any major problems.
The only problems I've encountered are (occasional) increases in aRts processing delays, and Xine. swsusp2 will not hibernate properly if Xine is running, likely due to hooks into the video hardware. The aRts problem is a bit mysterious, but likely fixable with a restart of the daemon, I just haven't tried.
I want to ditch aRts altogether but there are some features of it I'm using in my frontend, mainly access to FFT data for the spectrum analyzer.