I have Helios PTC on both tanks (50g and 26g) for 2+ years and have been completely satisfied. Temp probe and heaters have to be cleaned occasionally but isn’t cleaning and maintenance our routine? PTC can pair any of its heat elements so on the 50 I use 200w + 100w, providing swift correction after WC (I rarely preheat new water) with time-buying reserve power in case the 200 fails. Temp never varies more than 0.5. I don’t have Apex but the lo/hi double-failsafe on Helios has earned my trust. No elements have yet failed, either. (OK, I keep my old Eheim Jaegers in the storage room just in case.)