Personally I use
Lounge Lizard (Rhodes/Wurlitzer)
Pianoteq (Acoustic Piano) – although it does a decent Rhodes/Wurlitzer as well
Blue3 (Hammond organ)
All of the above use physical modeling so no samples and the CPU usage is fabulous.
NB - there is a discount available for Pianoteq if you are a Gig Performer user. We don’t receive any portion of such sales. Please see this KB article first to understand why.