Yes, fenders work. I really dislike the times I'm caught in the wet on a bike that doesn't have 'em.
I have a few bikes with Planet bike and SKS fenders. I've not had issues with either. The main factor for good results is buying the right width, and taking the time to do a meticulous install.
I also don't find I need (or like) long mud flaps. Maybe if I was riding in rain more often I would.
I especially like the look of the painted to match PB fenders on my Raleigh. I shortened the rear for looks, less weight, and because I often wheel the bike through my shop and garage on the rear wheel. (long fender would scrape the ground) I never have others on my tail in the rain to be concerned about spraying them.
