I have three of the new U33c/U36c's. Lionel made a lot of changes since the first release a decade ago. These new engines are the most realistically geared AF engines Lionel has released since the 4014 Big Boy. I can actually use the real railroad speed selections on my Cab2 with these engines. The smoke units are also greatly improved for those who are fans of smoke.
I usually run them in Legacy mode on my layout, however I also run them conventional on a small carpet layout. They work great. With whistle and bell buttons the crew talk and tower comm can be actuated as well as the whistle and bell. Only downside is there is no way to open the electrocouplers in conventional.
I just bought another Y3 from Ro yesterday when I saw the sale.