Vic,
Both control systems are just fantastic but different, no doubt about it the Legacy is very user friendly and easy to install. DCS is a more complex engineering control system, that is one of the reasons DCS can control Legacy engines, but Legacy can not control DCS engines, except in conventional mode. If you happen to like P2 & P3 engines, purchase the full DCS, get Barry's Book and the OGR Video guide to DCS, and learn to operate a DCS layout, then add the Legacy to your DCS layout. I run FasTrack and the one big advantage Legacy holds on DCS is that Legacy runs FasTrack wireless
Command Control switches, which I have come to really appreciate. No more switch wires with FT CC Switches, so I run both DCS & Legacy on Fastrack and get the best from both operating systems. It took me a long time to add Legacy to my DCS layouts, however the FT CC switches gave me the engineering reason I need, to make the investment. It is a lot easier to add Legacy to the DCS than the other way around, and believe me you are going to want both eventually.
PCRR/Dave