I have a Pentax Pioneer 3x9 which I won in a draw. The scope is actually made by Burris and is a Fullfield !!, it has the ballistcplex reticle, which I don;t really like for hunting, it is fairly clear and brigfht, but a little fuzzy around the edges. I mounted it on a ruger 10-22 and for that purpose it's great.
I have owned two Pentax scopes; an older 4x, and a Pentax LightSeeker 6x-24xPA. The 4x was (foolishly) sold off when I went to a 3x-9x on the rifle it used to ride on; the 6x-24x sits on one of my .223 varminters.
The LightSeekers are excellent scopes; the optical quality is very high (clear and bright), and the adjustments track true.