No, it won't matter. Things will die before you reach the slow cap so using CE and AR for that purpose really is a waste of time. Ice/Ice is a nice combo, but focusing on the slows is the wrong way to go in my opinion.
"People love to talk, but hate to listen." Alice Duer Miller, American Author (1874-1942)
So, no way to slow them so much they are moving and doing everything else backwards? 
This isn't specific to slows, but it explains how -Recharge works:
http://boards.cityofheroes.com/showthread.php?t=218111
In my opinion, the reason to go ice/ice (besides theme) is so that between your AoE slow powers and your attacks things are slowed to smithereens incidentally without you really having to worry much about it. Chilling embrace, though, is not part of that as far as I'm concerned.
Basically the problem is that, in my opinion, chilling embrace is redundant with arctic air instead of complementary. Arctic air with even 1 slow enhancer (mine has a pair of end/slow/rech IOs in it, which works out to 1 slow) slows stuff effectively to a halt already. It also applies a -50% recharge debuff, which is most of the way to the -75% cap.
Chilling embrace doesn't really add anything to what arctic air already does. It doesn't add anything in terms of movement slowing, since anything within its meager 10 foot radius is already within arctic air's huge 25 foot radius and moving at a snails pace anyway. And it doesn't add much in terms of recharge slowing, because its very small radius means that any one foe won't be in range for very long as you bounce around and they try to run (very slowly) out of range.
In any situation where you'd actually want more slowing than what arctic air provides, chilling embrace doesn't really help since it's basically arctic air's baby brother. If the situation is such that arctic air is ill suited to the task (such as foes who are so dangerous up close that you don't want to melee them), chilling embrace is also more than likely disqualified. If you want a second slow to back up arctic air, I'd instead look at shiver. It requires little slotting (just a bit of acc and recharge), has a huge area of effect, and its nature as a 'sticky' click debuff makes it a good counterpart to arctic air.
@MuonNeutrino
Student, Gamer, Altaholic, and future Astronomer.
This is what it means to be a tank!
I was thinking of going ice/ice. The thought of arctic air + chilling embrace gives me chills! It just made me wonder about the max you could slow mobs? I want to be able to stack both of those powers, but will they stack and to a degree that matters and it noticeable? TYVM!
PS: This question also kinda concerns the new MM I want to make Demon/Storm. I am also hoping to mix the demon princes chilling embrace with snow storm!
"I have always been a fan of science fiction. It all started when my parents forced me to go to church when I was a child."