chk,
Like everything else, it depends on the actual product line. Leupold has lines from VX1 to VX2 to Vari-X III to LPS, and whole bunch of other lines in the middle. Prices, and quality, therefore ranges accordingly.
The top of the line Pentax scopes use very high quality glass. However, I would not say that they are much better, if at all, than the Elite 4200s.
Like you, my only complaint about the Elite 4200s is their very short eye relief. I wish they were at least 4". The Leupold Vari-X IIIs have some of the longest eye reliefs out there!
Zachary