I was looking at the MC Operator and Colt Rail Gun recently, and went with the pony.
Having had five or six various Springfields over the years, and knowing that I would get a good quality product made me want to try something new just for the sake of newness. My current Springfield is a Loaded, on my hip as I type this. The new gun would have a rail for home defense/concealed carry.
I went with the stainless pony, because that’s what was available. I have to say, as I’m breaking this pony in, that I am impressed with the reliability. I’m also impressed with the various Springfields, and their reliability, so that’s a wash.
Customer service, what’s that? I haven’t had need of that from either company, but it’s nice to know that it’s there if issues arise. I have seen someone from Colt frequent other forums, and the issues that come up seem to be handled satisfactorily for all concerned. If this person is being paid to respond to internet post I applaud Colt for doing this. If this person is doing this becase he or she wants too, I applaud that also. It speaks of a love and commitment to the employer and product that is too often lacking in today’s world.
I don’t think one would go wrong with either choice, and they both will need the same basic stuff to get them up to par for Duty Carry, IMO. The one exception may be the sights on the Springfield, if you like three green dots, I don’t. The Colt will most definately need a change of sights unless one likes three white dots. As for sharp edges, I haven’t found the edges on my Colt to be all that sharp, but then again I use pine needles as toilet paper, to give you an idea as to the softness of my skin. 
One thing that pushed me in to the Colt camp over the Springfield was that I had no desire to disable the lock on the Mainspring Housing by changing the Mainspring Housing. The Colt doesn’t have the lock feature, but does have the Series 80 feature. Colt has been doing the Series 80 for quite a while, and I have not heard of issues with that feature regarding reliability so it was a non-issue for me. The bigger issue for me was being seen as someone reckless enough to disable a safety device on a firearm if I went with the Springfield.
I have a Springfield Loaded on my hip as I type this. It too has the lock feature, and hasn’t been an issue, but I don’t like it as it reminds me of political issues best forgotten in my opinion.
I currently have 500 rounds through my new Colt, with various rounds, and plan to put more rounds, 250 rounds, through it later this week with the TLR1 in place on it. After that I will continue testing it with my carry ammunition, 300 rounds total. That will put me over the 1,000 round mark. The way the pony has been running I don’t foresee any reliability issues coming up, but one never knows. I’ll post back if issues come up.
I wouldn’t hesitate to recommend the Colt Rail Gun or the Springfield MC Operator as duty guns and I’m coming to the opinion that guns need lights on them for serious use. You won’t go wrong with either one I think. Another issue that led me to the Colt was the relif cut under the Trigger Guard on the Colt. It works wonders on allowing one to obtain a very good grasp on the weapon, and that was the final selling point for me, as my range scores have shown.
Biker