Hi the £650 shops are currently selling it at is including import duty & their mark up (approx £100) which is why the price is so high, the noise level is virtually none existent, much quieter than the biomaster/biotherm & so far not drew air in once which the biomaster filters do frequently for some reason, the flow rate is also much better than the Oase filters but the 1 plug for everything is definitely the best, as I say in video I had the 850, 350, the 2 heaters & an inkbird so it didn't favour 1 heater over the other, now I have 1 plug instead of 5... this is the best filter I've had by a country mile, the prefilter sponge is also much easier to deal with, getting the 850 one out was sometimes a real pain as you need almost 2ft of clearance!!