Since I was the one that started that thread, I guess I'll chime in. I actually have ordered my new tires. I went with Pirelli Sport Demon in the factory sizes. Several reasons for this:
1) PSD are bias ply, which the rim is apparently "designed" for. However, they're about as radial oriented as a bias ply can be.
2) Stock size is what the bike is apparently "designed" for. So far, the only reason I've found to change to a wider tire is looks.
I did a lot of research on the issue and I know there are lots and LOTS of opinions about tire sizes, but for me, dealing with a new bike and new learning curve, the last thing I wanted to do was experiment with radials or larger sizes when it seems most of the 'experts' recommend sticking with stock construction and sizes. I did think about going with a 140/70 rear, but I couldn't bring myself to add weight and overall diameter simply to have tire that may look a little wider. I've taken the stock 130/70 all the way past the edge of the tire, so a wider tire would be nice, but so far even at extreme lean the (stock) tires still hold ok.
The reason I got new tires was because I got a nail in the rear at only a few hundred miles. Even though the tire has still never leaked at 1200 miles, I don't like the fact that it has been damaged. I didn't want to replace the 'moped' rear tire with another of the same, so I bit the bullet and replaced both front a rears. The next go around with tires, I will reconsider wider tires, but I feel better just sticking with what I think I know this time around.