A good idea to decrease construction time?  Seems kind of pricey?  Any brands you would recommend and why?  Thanks.

I should clarify that I mean a product like Crete-Heat: http://www.crete-heat.com/

If you want to make the install fly, they sure do the trick. My client reports are that it's ridiculously fast.

there is a very small performance hit, and it is pricier than plain insulation with wire mesh/ties.

so it all depends on how time is valued on your particular project.