I don't know if comparable is really accurate in my experience. Most of my coworkers use XP or Vista, I use Ubuntu. They may not have to reboot as frequently as they did in the old days, but I'm the only one seeing the "It has been 192 days since your last reboot" message when I reset my computer. Consumer grade Linux probably gets 3-4 9s, Consumer grade windows maybe gets 1. Both are good, but one is several orders of magnitude better.