Jason, I run both types of outfits side by side in various weights. I have PE3, 4, and 6 in spin and conventional and PE8 in spin only. For what its worth, my observations are;
1) I prefer the overhead for "mechanical"speed jigging with bottom weighted jigs (I can settle into a nice rhythm), and jig from under the arm.
2) I prefer the spin gear for "flipping"centre weighted jigs using a more technical style (I can get a more varied range of rod movement from the spin gear) and jig from the belt.
A couple of other factors to consider include;
1) I have limited wrist movement and find the conventional gear easier to grasp when used under the arm
2) The height of the gunnel of the boat you fish from might limit your ability to jig from the belt (in some cases).
3) For a long day jigging, I continuously swap between the conventional and spin gear (and centre and bottom weighted jigs) to mix up the muscles and pressure spots on the body. I can jig longer in deep water that way.
One additional general note is that spin gear can generally fish higher drags (although there are some conventional reels now sporting very high drag ratings) yet conventional reels have a greater range of spool sizes (allowing deep jigging with heavy braid)[/li][/list]
There you go, horses for courses really - if you are just starting out, get whatever outfit you can, and develop a style that works for you..........I'm sure it wont be the only one you own in the long run!