Yes, they are plugins, so can still use files from older versions (I *think* DP 1.5 came with X2 though, but cannot remember now). X1 and X2 run independently, so unless you are hurting for file space, I would NOT recommend uninstalling X1. X2 as it loads will actually use your preferences from X1. I still use VST plugins from SONAR 7 at times. In X2, you can simply add paths to the old VST's in the VST plugin and scan those folders manually in the preferences (or even allow them to scan each time X2 starts).