I've personally had 3 Colts I sent back to Colt for repair. If your Python needs re-timed / repaired for lockup, call in first. Knowing Colt, they probably changed again which they will work on and which they will not.
I had 3 Colt DA revolvers which all needed work as stated. A 1953 OMM 22LR (it was actaully a friend of mines, but I sent it in), a 1954 357 model (before the Python) and a 1968 Python.
In all 3 instances, the gun would either move out of alignment manually when the hammer was back, or when the trigger was held back. When the hammer is back, the Colt should hardly move at all, and definitely not out of alignment. When the trigger is held back, the lockup should be the so called "tight as a drum" and there should be ZERO play. Calling in each time, Colt confirmed that the gun needed service. The Python and the OMM were $85 (labor plus return shipping) plus the cost of sending to them. That was well worth it. However, the 357 model needed IIRC an extra part which also meant more labor, and that bill was $180 approx, plus return shipping, about $195 total, and of course the shipping to them. Luckily I didn't pay retail for that gun.
I've shot and encountered many others, and they were fine. I would say however, that the issue is common enough to where you should check the revolver thoroughly before purchase. Colt actually does not work on most of their DA models, so if you encounter this problem with say a New Service, Cobra etc you are out of luck. For the record, they work on very few of their models, at all. IIRC they don't work on Woodsmans, Cobras, any pre war revolvers, etc. I decided one day, for future reference to ask which they do and do not work, and the "Do not" list was substantially longer.
My friend decided to sell the OMM after getting it fixed and I sold my Python after getting it fixed. Due to the scarcity of the 357 model, I have kept that gun.