I've had a superday for the last 7-8 years and like it. I especially like the built in holster for my pistol in the hip belt. The only thing I don't like about it, is that you have to take it off to access the large hip belt pockets.. Other than that, this thing is bullet proof!
I had an older 4500 for a few years as well. Worked well, I just didn't like the lack of pockets. I sold it and am happy with its replacement.