I am running my first set of ITP Mud Lites, as they were part of the deal on my quad. They pull and handle very well, so far I am impressed with no issues in 1000miles of variety use.

SJ's suggestion of the Maxxis Mud Bugs or GBC Gators is also a good one. I ran the bugs previously with great results. Also have a few buds who run the Gators & ITP 589's with equally good feedback. The 589's IMO have the roughest ride on hard pack of these mentioned.

Another decent mid level at is the kenda bearclaw. I have gotten good results from these on my lake units that see more hardpack but also the odd bit of slop. Not as strong as the others mentioned interms of mud or skeg/tough sluggin' but not a badskin with a nice ride.

Heard nothing but good about the fore mentioned Mudrunners, but too rich for my blood[&:].

Sorry haven't heard anything about the swamplites you mention.

Good Luck