i have never been a lover of themos normal heaters only last 5yrs max a normal ehiem lasts 10yrs+ so does that mean the filter will last 5yrs longer than the heater
keep it simple if the heater brakes it means you need to shut down the whole tank filteration to get it fixed
im also getting a pair of rena filstar xp4s, so filter wont b issue. anyway, the heating elemant would be an ebojager (eheim sect) and those things r basically indestrucible