i have recently compared my static tipped RER Retro (53#@28", 58" length) with my new static tipped RER LXR (52#@28", 64" length), and that seems to be the perception for me. shooting the exact same arrow, the Retro seems to be a bit "snappier", although i think most of that is simply perception on my part, due to the smoother draw of the longer bow.
i plan to chrono them at some point and see just how much difference in speed there really is. really interested to see how it shakes out.