I'm fairly accomplished on either bike, GSXR or Motard. I also love pushing other bikes hard through the twisties, I have scraped pegs two-up on a Concours and ground the ends off of the pegs on a meanstreak.
I love the MonoGP bikes, but to me they lose a lot of the advantages of a 'tard, you lose the long-travel suspension, ground clearance, and especially important the leverage of the wide bars. They're a great alternative to a 125 or 250 two-stroke road racer, and they might be the best "starter" sportbike in existence, but to me they're not an alternative to a tard. They have no advantages over a tard and on a tight twisty technical track a tard would win, more cornering clearance and more leverage in the bars means better handling.
Oh and BTW, the RC4 has the same basic motor as the SMC, so neither bike needs a rebuild that often.