Lou is awesome. This is return business - I had him upgrade the first TiVo I had (which is still in service), and a couple of months later I had some problems. At first we thought it was just a software glitch, but after sending the unit back and forth a couple of times it became clear one of the drives was failing.
Anyway, Lou replaced the drives at no additional cost (I paid shipping to him, he paid shipping to me), under warrantee. I was *very* pleasantly surprise, and though I could have done this upgrade myself his warantee is well worth the cost of the service.
I highly, highly recommend PTVUpgrade.com.