I don't have much faith in the reliability or durability of any processor that doesn't have a fan. People seem to think that because their electronics are now wrapped in attractive, minimalist cases, that they are better or will "just work." In many ways you're actually sacrificing performance for aesthetics but that's what sells. There are so many devices being sold today that can't handle any extended load without locking up and (maybe) rebooting. Lookup the max operating temp of an iPad, its something like 95 degrees F, that's going to happen pretty fast in the sun with the screen on. If it had a fan, nobody would buy it but it would be much more robust.
A good example is my asus router, it would start dropping tons of packets whenever someone did a large download over WiFi and would need a reboot/cool down before it could be usable again. I dremeled a hole in its pointless case, put a 120mm fan over it blowing onto the heatsink, and it has never done that again.