I am glad you like the Legacy collection Dave. I think it has some great sounds in it. As one who plays keys though, what I think I hear you saying is that your customers want something that sounds good, is not difficult to dial a sound and just works. I would keep both a hardware rompler like the Motif and the software as well.
When I play I don't want to be bothered by the latency you might get with a VST. Guys who play keys live for a living usually have something they can access fast like a hardware rompler. That way you can track both the "live" rompler sound as audio and a midi track of their playing. Later on you can add any VST instrument you want. I know you can get the latency to almost nothing but I still prefer the "feel" of the hardware. To me this is the best of both worlds, in direct monitoring the hardware and using the midi track. Sometimes I mix the two, sometimes the audio track sounds better, sometimes I scrap the audio track and take something from one of my VSTs.