Ehiem Quick Vac PRO - Automatic gravel cleaner

So i got suckered into purchasing a Ehiem Quick Vac PRO - to be 100% honest  I have been curious to trial it out especially since I was experimenting on how to speed up cleaning/filtering detritus off a glass tank bottom which didn't contain any gravel. I have to say for picking up the small pieces it does seem to work rather well however, keep in mind if you have a large amount of detritus it will get clogged rather easily.

It works by sucking up water through the siphon part at the bottom then pushes it up into the clear bag portion (between the handle and siphon - which I think is semi porous) which traps the detritus and lets the water back in the tank. Don't shake it to hard or the detritus will follow the water back into the tank especially the smaller particles.

So the first unit i opened up was faulty .... so I sent that one back and got another - this seemed to have way more suction however, nothing major i.e. it isn't even strong enough to lift one tiny piece of gravel off the aquarium floor however, lighter bits of detritus gets sucked up easily enough. Operation is rather simple and assembly is as easy as pie. To turn the unit on/off there is one button on top of the handle - you don't need to hold it - it just stays on and then press again to turn it off. It doesn't function well if you take it out of the water whilst still on and then plonk it back in the water as it seems to get air locked therefore you need to turn it off and on again to get it going.

I used it on a area that had a small build up of detritus and, it seemed to function well and, to clean it I just took the bag out and rinsed under tap water. However, in the tank with large amounts of detritus I just found it useless as it kept getting full really quick and I spent more time going back to the sink to to clean it.

OK so I rate this device a 6/10 - the concept is great however, the suction power isn't..... and the bags can't handle much detritus.... seems to trap larger particles well  but, no so good with the smaller ones.... Also tried it on a gravel based tank and to be honest the traditional gravity feed gravel vacuum works 100 times better. 4 hours battery time - so make sure you use rechargeable ones :)
So save your money for when they bring out a automatic gravel vac with some real vacuum power.