The only real way to find out is to ask Dawid : you can e-mail him at This email address is being protected from spambots. You need JavaScript enabled to view it. : Dawid is a really nice, helpful guy and I'm sure he will take the time to give you his view!
If you want the benefit of my experience, having upgraded from an Elite to an SL (both in carbon) about 4 months ago, then read on. If not, stop here!
The first thing is that the SL's primary stability is a lot less than the Elite, and when I first got my SL my core muscles really felt it! The secondary stability is good, so I never felt like I was going to fall in, but the lower primary stability took a bit of getting used to.
In terms of speed, I haven't done any measured comparisons so my comments are subjective, but the SL feels a lot better going into the wind where the finer entry means it cuts through the chop better. The same can be said for small downwind runs where the SL seems to accelerate onto the runs quicker.
In bigger downwind offshore conditions the two skis behave similarly, but here the Elite's greater stability and extra volume up front means it steers better on the wave face and coming in through the surf, where the SL broaches more easily.
The SL is definitely a more demanding ski to paddle as conditions get wilder, and Dean Gardiner summed it up well when he said the SL is only faster in the hands of someone who can master it.