I've had over40 boxed train sets, with and without track & transformer dating from 1990's versions through 2020, all makes, Lionel, MTH, ATLAS, WILLIAMS.
On today's new market I favor Lionel's Lionchief sets with fastrack. Great value and fun to run. I have 3 now and 3 more coming later this year. The power pack is plenty, I'm powering a Lionel double pretzel layout with their standard plug in 74 watt power pack, running HOGWARTS EXPRESS with 4 illuminated cars, on at least 60' of track with 2 crossovers, 036 curves. You can also adapt the layout to run transformer controlled engines (standard Lionel MTH, Atlas, Williams)
I use to by MTH their trains and transformers are great, track is not as good as fastrack.