I have the exact opposite experience as you. My Ceton card in my HTPC is rock solid 24/7, records everything I want it to, and I cant even tell you the last time I even rebooted the tuning adapter on it. Sometimes I even forget it has one. I pretty much never have to do anything to it but just watch the shows it records, and once a month make sure I reboot it when the Windows updates download. Been trouble free so far
Now the XL4, that thing I have to literally babysit all the time. Its a constant struggle to get it to record what I want it to, and I'm always running to it at the top of the hour to make sure its actually recording something. Its gotten so bad that its in my office at this point. I cant even trust it to record my good shows. It's like I am constantly pulling out the cable card, rebooting the tuning adapter, or leaving the tuning adapter unplugged for awhile so it can populate suggestions. I'm hoping the fall update will take care of a lot of this, but if it ends up being the "same ole same ole" then when the contract is over, I'm gonna have to figure out something else.
Really got excited about the Roamio when it came out and held off on getting one to see the feedback, but it looks as though some of the people are having the same issues that I have now, and that was a downer.