Comfort and best protection/least printing....just curious.
If you are going to train with you carry gear (and you should), I feel a covered muzzle is very important in an IWB holster. That muzzle will be warmer than what you want stuck inside your pants!
True, but one doesn't always have to immediately stick that hot pistol right back in your holster and down inside your pants when finished shooting at the range. I can, however, see some training scenarios where full coverage would be a good thing indeed.
"Shooting at the range"? or "Training" Yes, going to the local range where you cannot draw from a holster and laying it on the table after you are done should not cause a problem. Real training where you are drawing from a holster and firing rounds is a different animal. And that is what we all should be doing. I've attended 35+ instructor led training classes in the past 18 months. In all cases the guns were holstered almost intermediately after shooting a drill. I used an IWB holster in many of those classes, in some cases drawing from actual concealment as I would have to in a self-defense situation. Those drills were anywhere from 1 to 15+ rounds but on average 5-8 per string of fire. I wouldn't want that hot muzzle against my leg or crotch. I've brushed my arm against the muzzle end of the slide of a slide through OWB holstered gun several minutes after a session and it will get your attention in a hurry. If you are involved in a self defense shooting you are going to want to holster the gun as soon as the threat is cleared.
My vote is still for a full coverage holster when used IWB.