I used to be really big into distributed.net and was ranked pretty high. One big reason that I stopped though was due to moving to more thermal controlled systems with dynamic fans. First my Shuttle XPC, and most recently to laptops. Having to hear what would normally be a quiet machine turn into a beast as noisy as full desktop PCs got on my nerves quickly.

I also see no concrete benefits from these programs. Many sound good in theory, but lack any real world results now after years of being out there. I'd much rather donate my money directly to the scientific communities involved in real research instead of handing that money over to the local energy company by having my system run 24/7 full tilt.