I used Hoya Pro or B+W filters on all my lenses when I started out and I was shooting with a 550D and the kit lens, a 55-250 and then got a Tamron 28-300 VC instead. I didn't notice much, if any degradation when using them on this equipment. However, after being left some money in a will I got a 7D, a 100-400 L and a 100 f2.8L Macro. The IQ really took a hit when I had the 100-400 on, with a Hoya UV filter, on the 7D. It was so bad compared with the 550D that I was on the verge of returning the 7D when I did a shoot without the filter on and there was a world of difference. Since then I've only used UV filters if I'm near the coast and there's salt spray and sand blowing about or if it's pouring with rain or it's very windy in a dusty environment. I always shoot with a hood on, if they don't come with one I'll buy one for the lens, and I've never had any problems with any of my lenses due to dust. I've had only one lens go bad, an 11 month old Sigma that got a focus problem (nothing to do with filters).