Oh..this is an easy...
(1.) Factory Loaded 45 Long Colt is more controllable.
Pros and Cons:
If you do NOT load your own ammunition and are never planning on doing so, AND you are NOT going to compete in Cowboy Action Shooting AND you are concerned about the cost of FACTORY loaded cartridges. Then choose the 44 Magnum.
The 45 Colt is more expensive if you are buying ammunition. And there is a greater variety of Factory Loaded 44 Magnum Ammunition out there.
BUT the 45 Colt is really a superior round to the 44 Magnum. The reason is its case capacity.
But to take advantage of its superiority you really have to load your own rounds. The larger case capacity of the 45 Colt allows you to load a round that is more powerful than a 44 Magnum.
If you load to 44 Magnum levels..a 45 Colt will push the same grain bullet at the same muzzle velocity as the 44 Magnum BUT at LOWER pressures.
In general loadings the .45 Colt will do anything the .44 magnum will do with about 6000 to 10,000 CUP less chamber pressure, depending on the load and bullet weight used.