I agree, these new/old Pacifics are very nice with the Legacy system. I have three of the new Pacifics, NP, NYC and AT&SF. Also have seven of the old Pacifics and Mikados, all modified with cruise control, half speed worm and an MTH fan driven smoke unit.
I noticed the three new engines needed several hours of run time for break in. At first the operation in the first four speed steps was irregular/inconsistent. They now run much better at the lowest speed steps.
Here are pictures of the NYC running on speed step 10 and the old TMCC B&O running a little faster, around speed step 25 (out of 100.) The top speed of the new Pacifics is much higher than the old ones modified with a half speed worm (courtesy of AM.) The smoke fan in the new Pacifics has much more lift than older Lionel AF engines and more than this MTH fan unit has. I like smoke, can never have too much.
I really enjoy running these new Pacific engines, nice to have the electrocoupler.