7.62, you know you wanna buy a gun just for the sake of buying a gun!!!
It happens to the best of us. "Upgrade" is our way of justifying the purchase.
J/K.
If it were my money (money were a concern), my predicament, and my "upgrade" decision I would opt for one of the following:
1. Purchase another Mossberg 500 Persuader (especially if I were already familiar with the manual of arms)
2. Winchester 1300 Defender, excellent shotgun for the money with a very smooth action making this one of my favorite pumpguns.
3. Benelli Nova Special Purpose which is also another good bang for the buck. Smooth action and can take 3.5" if you REALLY feel the need to spend cash.
I've handled and fired all of the three and I'd opt for #2 or #3 as I am not a tang-mounted safety sorta guy. However, I'm assuming that they work well for you.
My girlfriend has a Nova SP and is a dream to shoot. Robust action (most pumps are) and easily disassembled and cleaned. Not that it means a whole lot in a scattergun, but Benelli chrome lines their barrels. This makes it just that much more easier to maintain. Benelli's "round cutoff" is a plus. You can cycle the action to clear the chamber without throwing a cartridge on the carrier. Not a big whoopty doo, but it is a nice feature. The downsides are availability (in some areas) and lack of stock choices.
A few of my friends own the Winchester 1300 and just like the Nova, is a dream to shoot. Very smooth action and light. All of the specimens that I have examined were all built very well and quality control seemed great. Manual of arms is very much like the Nova except for the round cutoff and action release (which on the Win1300 is where I think it should be) which is near the rear of the trigger guard.
OR you can do as others have mentioned which is seek training (if you haven't done so already). I for one whole heartedly recommend this option. But this thread isn't about that, is it? It's about buying a new gun!!!
Jim