Depends on what you are looking for.
If you want a decent VP with a CMS (color management system) then you can also look at the DVDO Iscan Duo. Does most of the standard VP operations (up/cross conversion, switching, pic control, etc..) and works with the most popular calibration utilities (CalMan, Chromapure) in interactive and auto cal modes. It can pass 3d through, but the CMS cannot be used on a 3D source. It retails ~$1000.
The Lumagen is a step up from the DVDO Duo. Depending on the model it is ~$500 to $1500 more expensive, has more controls, is updated more often, has more high end pic tweaks and is more flexible. Its CMS model is more advanced than the Duo. It's CMS can be used on 3d. However, its interface is generally considered more complex and the learning curve steeper than the Duo.
Both are well regarded. I have a DVDO IScan Duo and use both Calman/Chromapure with it to tweak the pic and get the colors in line. It makes significant improvements with my JVC RS40. I may get a Lumagen down the road, but I am happy with the Duo.
Edited by bairda - 6/7/12 at 2:08pm