Got a newly constructed walkout (two-walls of 12" concrete block) basement, outside coated with black goop waterproofing and Green-Guard foam (about 1/2"). Getting ready to put up the interior walls and am a little antsy about how to insulate them against the block walls.

I want 2x4 walls to ease electrical installation, and am considering 2" foam boards between the studs as opposed to wafer thin continuous foam board with studs on top of it. Research suggests fiberglass batting and vapor barrier is a bad idea.

Any thoughts?

That is a good system.

But even better is to glue up 2" of foam and then build a wall infront of it.

Faster than cutting all of the sheets. And it isolated thw wood (if you are using wood) from the concrete.