The reason why Lockheed got out of the civilian airliner business was that they were too good at what they did, so good to the point that there wasn't any money in it for them. Airliners have slim profit margins, sometimes none at all. Essentially, they are cattle cars for the masses. So to compete in the airliner game, you must adopt the industry mantra: make them reasonably reliable, make them reasonably simple, and make them reasonably cheap. And sell, sell, sell. Make a dollar profit on each one, and sell a million. When they crash, make the appropriate adjustments on the next batch
Historically, Lockheed products didn't fit that mold. They made them ultra realiable, they made them ultra advanced, and they made the adjustments before they crashed. As a result, they didn't make them cheap. Such as airliners are, they needn't be built by a firm like Lockheed whose engineering talent was wasted on such cattle cars. Especially so considering how they were so good at making expensive, exotic, technical wonders for the military in limited quantities. And that's where the money is, anyway. So that is where they are now. In fact, they are the prime contractor chosen by NASA to produce the Venturestar, the first reusable space plane. http://www.venturestar.com
Having Lockheed make airliners, was akin to having Ferrari make trucks. Ferrari trucks would drive great, look spectacular, but they would be more expensive to produce and maintain. Ferrari could never sell enough of them to make any money. That's what happend to the the L-1011 we all love. Regrettable as it was. So, GM makes trucks. Boeing and Airbus make airliners. Ferrari makes sportscars. And Lockheed makes space planes. There is order in the universe.
As far as engines are concerned, a GE engine, should be the mirror image of a Rolls Royce or Pratt & Whitney engine. There should be nothing that could account for any significant difference in reliability betwen them. The physics is the same for either company. The engineering is the same. The tolerances are the same. The materials are the same. And the engineers, who design these things, are also the same. They went to the same universities, earned the same degrees, and learned the very same facts of life. And I assume their pay is also somewhat the same.
Having said all that however, let me say I would prefer a plane powered by Rolls Royce or Pratt & Whitney engines over a GE powered one. But I have nothing against General Electric. They made my toaster, my refrigerator, my dishwasher, and they made the can opener I use to remove the lids from the cat food cans. And whenever I buy lightbulbs, I can assure you, the choice is clear. They know more about making light bulbs than anybody else.