I've had this blower out there for several years now and haven't had issues. This is my second blower becuase originally the HM used a 60mm blower, which I had designed the original RD around. I made a RD3 around that blower and it was just too big, so I found the 50mm blower with the same specs and built around that, later Bryan changed to the 50mm blower because it was more widely available and smaller (with the same specs). Still, I'd have to say this blower has been outside in the elements for about 3 years now with no issues.
The whole reason I went through the trouble to work out sending the probes over the CAT5 cable was so I can keep the HM inside but still connected to the RD3. It will operate well with up to about 50ft of cable, anything more than that the servo tends to flake out. I've only replaced the ends on the CAT5 cable about 2 times over 3-4 years, which also surprised me. I'm not even using outdoor cable, or any kind of sealed connectors, just regular cheap CAT5 cable and crimp on ends.