I peaked in the early 80's. Back then I felt like the Cheyenne Union Pacific yard........and now ? I'm an abandoned siding out in the sticks of a fallen flag railroad. .....not really, just feels like it sometimes.
I enjoyed TRS 2006 and stuck with it for a few years as after Trainz moved on to new versions. Working on a modern day Colorado route, everything seemed to be working pretty well, including signals, markers, rules commands and car traffic flow.
I hit bottom when I tried to upload literally hundreds of misc content made from GMAX but I think only one made the deadline for 2006 uploads to be put on the DLS. That was extremely disappointing. I could of upgraded the content for next version, but that would have taken a ton of time. I was frustrated and left Trainz for a for a few years.
I was also OK with TRS 2012, but made the jump to T:ANE SP3 , which I still use. Lots of the content I made over a decade ago doesn't look so hot in T:ANE, but slowly I'm getting them spruced up, if they fit into my current route in progress.
I think moving on to TRS 2019 would create a plethera of problems getting my old content to work......and new stuff because i'm still using GMAX and don't really have the patients or motivation to learn some new program.
I'd think that the performance would be much better moving on to at least T:ANE, but it might take a lot of time to get your old routes working like they used to. I could be wrong, but I think it's worth the risk, and T:ANE is pretty cheap right now.