I have used OrCAD with (OrCAD)Layout. IMHO: Crap. Cadence will most likely discontinue the Layout tool since they are pushing a "Lite" version of Allegro with the 10.3 release CD. The Capture tool is very nice to work with and one of it's big advantage is the vast number of different net list formats it can provide.
PCAD2002. Nice and with lot's of goodies but has some flaws particurlarly when it comes to design changes. ECO-files may fail to execute. Then layout has to be edited manually. I have seen some very nice designs created using PCAD2002. Unless you use the space bar for toggling when routing or placing wires in schematic, the pointer finger will be exhausted since it has to be pressed for the wire to be routed...
OrCAD Capture with Allegro Layout. A very nice solution except that it is almost a must to use the CIS-option to use Capture as a part oriented system. Forward annotation and ECO's works great! It is also easy to separate the layout from the schematic (Useful for consultants). Allegro is a very nice and dangerous tool. DRC check is solid and I have never seen it fail to miss an error. Learning curve is steep and Gerber file setup is really messy.
Mentor Expedition. Perhaps the best of them all, but with a high pricetag. Disadvantage: Complex system. Do something wrong with any of the files in the design folder tree and you are in deep shit! Mentor SupportNet is great though, and you will need it! This is a part oriented system, and the Library Manager is probably the best there is. Invoking it is akward, since you need an instance of Capture to be open in order to use the symbol creation module. Likewise an instance of Expedition (Layout) needs to be open if you want to use the cell (footprint) creation module. Otherwise, you must purchase a separate license for the Library Manager.
Mentor BoardStation: Unless you are working in a large organization: Forget it.