I've been carrying my stainless .45 ACP Colt Defender daily since I bought it in 2010. I bought it to replace the S&W model 60 I'd carried since I began my LEO career in 1979. I felt that with the proliferation of high capacity semi auto pistols in the hands of many low lives that the venerable 60 was no longer a good idea. The Defender would give me a couple extra rounds, a more easily reloadable pistol, and a more effective round than the .38 special +P I carried in the revolver, plus I'd been carrying an issued 1911 for nearly twenty years. Before carrying the Defender, I fit it with an extended thumb safety, some checkered wood grips, and had my gunsmith perform an action job.
Two years after I purchased the Defender, I took a plainclothes job within my department, so I decided that rather than carry my issued Colt Gunsite 1911, I would use the Defender as my duty gun. But first I dropped the gun at my local gunsmith's door for a few upgrades. The upgrades consisted of an upswept grip safety, checkered front strap, serrations on the top of the slide, a rounded butt, and a complete refinish of the stainless steel parts in Ion Bond, with the receiver anodized in black. My gunsmith also fit a polished steel feed ramp insert, and welded up and refit the barrel. I later fit a Wilson Combat bullet proof extended thumb safety to the gun.
Since then, I've carried the Defender in a Nighthawk Custom OWB holster at 4 Oclock on my belt. I qualify twice each year with the Defender firing about 600 rounds of 230 grain ball, and Winchester Ranger HP's through it annually. I use Wilson Combat magazines in the gun for carry, and will use the factory Colt compact mags during qualifications. I will also at least monthly fire a magazine from the gun with it in the condition as carried. In the time I've carried my Defender it has never malfunctioned with any of the ammo I shoot through it, even using the original Colt factory mags. At around the 2000 round mark, I began to notice some weak ejection, and at times could feel the slide surging forward while firing the gun. I replaced the original recoil spring assembly with another from Colt. This allowed the pistol to run smoothly again, and at around 4000 rounds now it continues to shoot fine, but a spring change is probably getting near.
As for comfort of carry, the Colt Defender is the most easily carried pistol I've ever had. I often forget it is even there and will sometimes let it be seen more than I intend. It is comfortable when driving as it does not press against a car seat with its Officer size grip, and it's short enough that the barrel does not push up from the seat either.
My only issue with my Defender is that as I've grown ten years older, I've noticed that I must slow down when running the gun. If I try to shoot it too fast I will drop rounds low on my target. I must concentrate on my front sight, and take a second to watch my trigger pull or I will drop rounds low.
I have no reservations about recommending the Colt Defender to anyone considering the purchase of one for use as their defensive hand gun.