I just implemented Mason caching for this website. I'm very pleased with the performance boost. Most notably, the news page seems to be better. I was parsing all the RSS files on every request and that was just crazy. Since my journal just spits out mason components I added caching to those as well.
On a sad note, the site is really screwed under Internet Explorer, any version. I don't know how to fix it without reverting to tables (there exist no tables for layout anymore). I have very few opportunities to use Internet Explorer and the only reason I care is that my wife uses that browser at work. I think in the end I'll have to revert to some kind of table. I'll still be compliant, but not as cool.