I think the VPI's could be better if they had mass. They don't. You need to operate a belt driven platter like a flywheel. It should weigh enough that you want help from a friend, ideally. Short of that I think DD/idler makes more sense. In that case a little decoupling and a little mat care goes forever.
Wimpy platters on belt driven things sound bad IMO. I haven't the slightest reservation in telling people low priced Rega's and Music Halls are bad choices. (I know, I used them for a long time)
Mat choice is the number one thing ignored that people underestimate. I used a herbies for awhile and it is better than felt, but it's still simply not good IMO. Herbies is for sale, $40 shipped...
($70 new)
Scott, get a cheap piece of cork from Home Depot, it could be off of one of their plant turntable things (mine is, the fancy stuff isn't as good that is too finely dense). Cut it smaller than the lip of the LP. Don't worry if it's a ragged edge, that's a good thing. Now put it on top of the stock JVC mat. Your record won't slip at all. Now Raise the VTA till it sounds good on a few records. There are numerous reasons why cork works well, especially on top of the rubber. No record weight... I hate them. What cart are you using?
The cheaper carts need the plastic stylus guards taken off. Then if they're the "box" style apply no-rez with foam removed on the board surfaces. Now when you insert it into the cart, if it has the slightly bit of play, use a tiny piece of paper to edge it tight. You can make something cheap sound kickass this way.