Yeah the car runs shitty when cold (I reset my ISC this morning.. a WORLD of difference... more on that later), my ISC wasn't doing anything and with the idle screw set for 950 when warm, part throttle was needed to start the car (just cranking it wouldn't start the car, just make it cough) and until the temp got up to the first mark (1/4), it would cough and splutter when driving, unless you fed it more throttle. (ie, you can't idle around in first when cold).
However I have an aftermarket ECU, so it may be different with a stock car, but I'm assuming that it's a similar issue to having no choke on a carbed car, the auto choke on my monaro was screwed and it was the same, and the webers on my escort had a manual choke which typically (haha for my cars) wasn't set up when I bought it - same deal. I just set the idle on the escort for 1200 though, and honestly the cam was so big it needed it
This morning I pulled out my ISC, wound it all the way out (I got it apart without breaking it) and put it back in... when I turn the key to "on", I can hear it click now, when I turn the key I get an extra 300 rpm (I set it that way) for a second, then back to 950, and when cold it idles at 1300. Nice. I guess if you have a stock car you're going to have to live with running crap when cold.. but on the other hand, when you pull up at the traffic lights next to a cop you won't have a surging idle, or be doing 1500 rpm randomly.. worth it IMO.