conroe will be good as we have seen in the benchmarks but it all depends on what your rig is now and what you want to go to.
Remember that if you have a socket 939 mobo at the moment then you may be able to fit an X2 in that board happily (might need a bios flash to support)
change to conroe and your changing chip, mobo and memory at the same time, possibly working out slightly more expensive in the end.
Personally I am loving the look of conroes power but my next upgrade will probably be to an X2, purely becuase it will be plenty powerful for my needs and much easier to make the change