I have a lot of stuff that runs both Legacy and TMCC. I'd be lying if I said that I prefer most Legacy engine sounds over the TMCC ones, but that doesn't detract from my enjoyment of the TMCC models. I also do a lot of upgrades to TMCC and PS/3, I like them all!
If there were a locomotive with TMCC and the same model with Legacy, I'd probably go for the Legacy unless the price difference was truly prohibitive.
@0-Gauge CJ posted:As time has gone on, I have gotten a better understanding of what I want and use in my models. For one, I've discovered that I have never bothered with any of the extra sounds and nice features (eg, depleting coal, refilling water, etc.). I also don't really use the crewtalk features. Sound is important to me, but the only sounds I really care about are the steam chuffing (including 4 chuffs per revolution), whistle, and to a lesser extent the bell. I also like slow starting and running too. I've also discovered that for some Lionel models, the tooling hasn't changed between TMCC and Legacy versions, just the electronics and feature set. Thus my attention turns to the TMCC version.
As you observed, you can upgrade to 4-chuffs in several ways, and also older TMCC can be upgraded to fan driven smoke, and further to properly chuffing smoke and smoke at idle. With a few enhancements, you can create a poor man's Legacy model from that TMCC locomotive.
I have the scale PRR T1 Duplex that is getting that treatment. It's never been made in Legacy, so I got the TMCC version. I'll add the ERR Cruise Commander M, Chuff-Generator, and the Super-Chuffer. I am also going to replace the existing Railsounds in the tender with all the RailSounds 6 stuff from the Legacy LionMaster T1 Duplex for better sounds. It won't be a Legacy model, but it'll run like one and sound like one, close enough! 
