I think he's a bloody good house producer - a shade better than most out there and his stuff is also quite accessible hence the success. But thats all it is - hes certainly no messiah...just a seemingly decent geeky guy who is very techy and knows his production...with a slight habit of putting his foot in it...
I personally think whilst his music is very well produced (as dance music) some of his creative decisions can be a bit lame. Starting off with the name - Im mean thats kind of lame, then the mousehead....and he uses some pretty questionable vocal hooks to his tracks - the vocal version of 'Hi Friend'' I found pretty suspect...The Mousehead thing is less of a shrewd marketing gimmic IMO than a bit of a joke combined with the fact that he does not see himself in the same light of normal House DJs because he doesnt really come from or is into the 'club' scene - he's more like a geeky electronic producer who ended up writing banging house tunes. So he sees himself as more of an artist than a DJ.
That said - I respect his work and what he has achieved hugely and all the Justice style bashing that goes on is quite petty and fairly transparent IMO.