I, too, have a Burn and love it. I have paddled the Remix a handful of times and here was my take on it:
Surfs well but nothing like the Burn
Not as stable (especially in the primary)
Boofs well (maybe better?)
Does not track as well
Turning: the Remix pivots better, the Burn carves better.
All in all, I would highly recommend the Remix; it is a very good boat and LL has the plushest outfitting around right now. That being said, I still like my Burn better and would pretty much always choose it over the Remix. In general, I have not had issues with the speed of the Burn that I could not make up for with paddling. If you're set on more speed, you might want to look into the Salto, too.
"The world would be a better place if everyone kayaked."-Brad Ludden (Valhalla)
"You only get one chance to run a drop blind."-DD