I personally think you lose a good bit of flavor when you filter. It's just a fast way to condition beer IMO.certain beers like Kolsch may be better for it but others like pales and iPas suffer.
I agree Keith. Filtering strips out hop flavor compounds and renders beer less hoppy. It also depends on the size particles that are being removed as well.
Particles and compounds are different things - I definitely don't want hop/yeast solids in my beer, but their flavor contributions are dissolved in solution. Filtering shouldn't strip out hop flavor just like it wont strip out malt flavor.
I guess this is just theoretical - I've never filtered a beer so I can't back it up with experience.