I used to strain, but I noticed that all that really got trapped was hops and any flavor additives (coriander, citrus peel, etc). Then I decided to try a few batches where I dumped everything just to see how they turned out because cleaning the strainer was a PITA. I couldn't tell a difference so I never went back to straining. I also frequently will re-use the yeast cake and have found that lack of straining causes no adverse affects in this regard either.