This is my first go-around with TMCC, which I had always heard was "easier" than DCS with its single wire connection to the outside rail. I've had DCS for about 5 years, and after working out a few bugs, it has worked extremely well.
With 6 TMCC-equipped locos, I have now added TMCC using the command base and cable connecting it to my TIU. So far, I have been able to successfully add and operate only 2 locos. The other 4 are unresponsive. I've followed the same steps with each loco, but no luck on 4 of them. I also have a TMCC remote, and have not had any success with it. Nothing works with it. The red light on the base flashes when I push buttons, but locos don't respond.
This surprises me because DCS is much more complex with respect to connections, but yet I've had much better luck with it than TMCC.
Has anyone else had this experience with the 2 command systems?
Yes, and No. Mostly No.
Out of the box and brand new there are few issues. Even old stuff usually has few issues.
You are apparently one of the unlucky ones.
Since you haven't indicated specifically what your problems are, other than "it doesn't work", everything can presently only be pure speculation on our part.
Start with a length of track on a bench and your command system, whether CAB-1/Base-1, Cab1-L/Base-1L or Cab-2/Base-2, and fire up your engines one at a time, beginning with your 'good' ones. Do not try to run any of your engines from the MTH handheld until you've sorted things out with a Lionel command set on its own.
There's some playing and learning needed with TMCC by itself here in order to proceed before throwing the MTH stuff into the equation.
I think that in the end that you'll find that you have just one or two simple problems to deal with, none of which are major.
Mike