I also bought one of the MTH Little Joes, and I have very mixed feelings about it. First of all, in my opinion, the price of the thing is absurd. This is the most expensive locomotive I've bought, and I only did so because I've wanted an HO Little Joe ever since the first time I saw a real one. But since we all have differing opinions on what a fair price and an absurd price is, I'll say no more in that regard.
As for the locomotive itself, it LOOKS wonderful! If I had purchased it to put in a display case on a shelf, I think I'd be one of the happiest model railroaders out there.
But I did not purchase it to just look at it, I bought it to run it, and in that regard, I'm rather disappointed. Fact is, the thing is so frustrating, that despite the absurd price I paid, I have been so tempted many times to yank it off the track and throw it against a wall. I have a home layout with conventional DC power, and I'm a member of a club with DCC, and my locomotive has seen run time on both layouts on multiple occasions. My experience with the locomotive has been the same regardless as to the powering system used.
I wonder if there is an electronic glitch in my locomotive, or if all the fancy stuff MTH put into it doesn't talk well amoung themselves, because my locomotive is a real pain to operate. I would say that maybe 35% of the time, it behaves just as it should, but the other 65% of the time, it just won't take commands. This has varied from it just not doing anything at all, to it running with one or more features not working, such as sound or lights or the power pantographs. Another repeating issue I have with it, is that it frequently ignores direction commands. I have had it light up and start making sounds when I power it up, but it won't move in either direction. I have had it run perfectly fine in one direction, but then it won't change direction. When that has happened, I have had it both continue running in the same direction despite having thrown the direction switch on the throttle, and I have had it just sit there and refuse to move at all. Weirdly, I have even been in the process of running it fine, then make a stop to rerail a car or something, and then have it not want to start up again.
My power pantographs have also never worked properly. Fresh out of the box, I had one working pantograph, and one that did nothing. I discovered that one of sliders inside the shell that make the pantographs raise and lower was off its track. Well opening up the locomotive and placing the slider on its track was quite easy, and after doing that, my pantographs worked for maybe two dozen cycles, and then started acting up. At first it was an intermittent problem, where sometimes they worked and sometimes they didn't. Then the times that they didn't work became more and more frequent, until now my pantographs don't work at all. Where as before it was a simple mechanical issue, this time its an electric/electronic issue. I've opened up the locomotive again, looking for a loose or broken wire, but all the wiring looks good, yet the little motors for the pantographs just aren't getting power. Apparently whatever it is on the circuit board that tells the motors when to work has failed.
Quite frankly, I would be much more pleased if this was a simple, plain-Jane locomotive without all its fancy nonsense. All I really want to do with it is put it on the track and run trains with it. I don't need sound, I don't need working pantographs, I don't need remotely operated couplers, and even directional lighting is something I could do without. But the fact that it has this stuff, and it doesn't work properly, annoys me no end. And the fact that many times it won't even respond to throttle commands to just run down the track without having to figet with it, makes it one of the most bothersome locomotives I've bought.