My Romio (basic) has been running with a temp of 46 (114.8 F) since January of this year when I first got it, and it has presented NO PROBLEMS that I can say were the result of heat. Yes, there were 2 times when I had pressed the TiVo Central button and it put the picture in the corner with the rest of the screen black for about 2 minutes, but that happens to my Premiere with far more frequency and can take an HOUR before the black portion changes to the TiVo Central display on my Premiere. I have to say, except for those 2 times, the Roamio has been a champ and not given me any other problems.
While the Roamio is in an audio pier with NO enclosures, quite in the "open" with LOTS of room for air to circulate, I fear the reason my Roamio runs far more hot than what others have posted on this forum is because it is atop my Hopper, however, the Roamio is raised several inches above the Hopper with lots of air flow at the bottom of the Roamio, but the Hopper runs quite HOT and I think a good deal of that heat rising does have the Roamio's temp gauge read much more hot than I've seen posted on this forum.
However, the point is that about 6 months running, not a single real problem. I do know that the high heat may present a problem in the long-run, but just to confirm, I've had no issues with the Roamio at 46 (118.6 F). It seems TiVo has designed the Roamios to tolerate the heat pretty well even with the less effective cooling cited on the Plus and Pro models. After the fiasco of the Premiere, I am so happy TiVo did the job right with Roamio. Now, if I can keep my self from buying another Roamio
.