I emailed surface skis and here was their response:
I have skied both on deep powder days (over 12" fresh) and both did
well but the LL2's required a bit less effort. The slight camber
under foot on the LL gives it the advantage on the groomers over the
LL2. So decide which you will be seing more of... are you the guy
that saves his legs and money until there's a powder day or do you ski
every condition regardless of whether or not it snowed. In reality
they are very similar but the slight advantage on groomers/ crud goes
to the LL because it has 3mm of camber under foot compared to the LL2
which is flat under foot. The additional rocker on LL2 gives it the
advantage in the pow (8 degrees of rocker on LL2 compared to 4 degrees
of rocker on LL1).
There used to be a bigger difference in flex but
not this year, the LL & LL2 are the same. "Stiff" is a relative term
and everyone's opinion is different. They are stiffer than an EP Pro
which was an intentional move so you don't wheelie out if you get in
the back seat. As to groomer skiing, I ski my LL2's almost every day
including the groomers. We have athletes who use the LL2's in the
park, so yes they are manageable on groomers due to being flat under
foot but have sidecut. The whole idea behind the ski was to make it
skiable and fun on the groomer as you ski back to the lift after a
sick pow run up top.
Here is a picture both skis from the side view(LL2/LL1):