I have three laptops folding for the cause, and none have any major issues. I do have one laptop (#130 on the charts) that is very sporadic about finishing WUs and reporting them, but I blame that on the user.
Are you folding GUI or service?
I'm using the GUI... it's been rock solid since March or so when I got the new machine... the last few weeks it just refuses to dowload a new WU. It sends the results in just fine... then gets stuck on downloading new work.
I can ping the IP address of the server, Stanford's stats say the sever is working fine... but day after day my laptop keeps saying that it cannot download a WU.
If there's some evidence that the service works better I might switch, but would prefer not to.