I replace mine at least once a year (rear), I have had a few sets each of PR2/3/4 and found them to be largely the same for feel and mileage (roughly 6-7k miles). I use my bike for the dailly commute (100miles) and the odd ride out with mates etc.
I decided to try the new Dunlop RoadSmart 3's this time and they have been pretty good. They seem to be wearing better than the Michelins, took longer to square off at least. The rear is also wider than the narrow Michelin (of the same size).
EDIT:
I will say, I replaced my rear wheel and the replacement came with a part worn Dunlop Qualifier 2 on it. This was a more sporty tourer than what I normally use but I left it on as it had plenty of meat on it. It was mega wide and looked the business, was good in the wet and also lasted a surprising amount of miles - I think I got about 4k out of it and like I said it was part worn. I was going to get a set of those but openeo didn't have any in stock when it was new tyre time...