I've had both eheim and fluvial. never had problems with either. the downside to the fluval is their hoses and their intake and outputs are HUGE!! the hose is no biggie, you can always replace it with vinyl tubing and custom output and intakes can be made cheaply out of PVC. the eheim I didn't really like, but they did the job. self priming doesn't exist, as was stated above. I just feel they are over priced and over rated. personally, I prefer fluvial canisters. I have used them for a long,LONG time without any problems. I've used their nano filters all the way up to the fx5. quietest filters I have owned actually. oh, and I have never had a fluval leak. eheims have leaked on me.