Tony,
If you've always wanted one, then don't let others persuade you.
The review on CN, appears positive, but the author hasn't drilled down on the specifics -
http://www.cloudynights.com/item.php?item_id=1287
I note your heading Pentax SDP 125. These are great astrographs if its all you intended to use them for. I've heard visually, they aren't very pleasing.
If you're going to go above the 500mm F/L, would suggest you look at the AP refractors. Long wait lists unfortunately, but they hold their value. Very impressive instruments. The 160 StarFire is a monster.