Decent hubs vs wheelsystem?

Hello,

I recently purchased two bikes: A 2014 defy advanced 1, with p-sl1 wheels, and a 2014 Giant TCR SLR 2, with p-r2 wheels on it. I personally like the TCR more than the Defy, however, getting up to speed and maintaining speed is easier on the Defy with the p-sl1 wheels. The p-sl1 wheels are also stiffer, however I am most interested in getting going and maintaining; I also want durability. Will better hubs help the p-r2's or will a second set of p-sl1's on the TCR (p-sl1 wheels much cheaper than asetof dura ace hubs.) P-sl1's are substantially lighter than the p-r2's (1500 vs1900). Will the lighter wheel do more than a good hub alone? Also, I have considered the Mavic kysirium equipe s, as I also want a compliant ride. I do not want the stiffest, fastest, most areo wheel, as I like to push myself for fitness purposes only and wish to be comfortable as well. Any thoughts from people who have good knowledge on wheels would be extremelly helpfull.

Thanks,

Andy