A Maverick 88 is basically a Mossberg 500 built with every cost-cutting shortcut they could imagine.
I've used a couple of the Mossbergs and have been very impressed, smooth functioning and about as reliable as a rock.
In fairness, I haven't used a Maverick, but I have held one a couple times and have not been real impressed. It was just rough and felt cheap. The stock was thin, loud, and so light the balance was terrible.
I think it was Flying High that had a Maverick, ran tens of thousands of rounds through it, beat the snot out of it and couldn't get it to stop working.
If the little bit extra money isn't a terrible hardship, I would heartily suggest the Mossberg, although I would prefer a wooden stock. It's better looking, warmer, quieter, and the extra weight will balance better and soak up the recoil better. I've found plastic stocks seem to amplify recoil a bit.