IMO I haven't had trainwreck like the old school stuff in nearly a decade.
All these IBL's are a pale comparison of the original from what I've seen and tasted.
After working with some Reserva Privada and DNA Genetics I can tell you that their train wreck crosses are about as close as I've come to that same "intoxicating" high. I'm pretty sure the Californian Collective of growers/breeders of RP had an original Arcata TW cut to breed with.
The Kandy Kush is Train Wreck and OG Kush. The following breeding project of these seeds with a Dutch sourced Skunk #1 produced a really fantastic and surprisingly stable F1. Cole Train is a cross of Super Silver Haze (Jasmine cut) and the same Arcata TW. The similarities between these two plants is pretty clear to me after growing out a few of each. The way the calyxes form and the pinkish hue to the pistils as they ripen is a classic trademark of both. Each has this somewhat sweet/fruity flavor though, gifted from the other heritage.
Real TW is very musky, woody, and pine-sap smelling. Sometimes the only way to describe the smell is "dank ass weed" because there really is nothing else that smells like it other than... dank ass weed. The high is nearly psychedelic, very cerebral, and once it is done you are ready for a big time nap. It's like a very refined Sativa start and a heavy Indica finish.
I grew up on Lompico TW in the 90's and it was incredible. Maybe not the best weed I'd ever smoked but it carries a kind of nostalgia for me.
Just do your homework on who has what cut of TW and where they got it from and when. The good stuff showed up 10 to 15 years ago, so those are the genetics you are after. All this crossing and inbreeding and back crossing has not helped the reputation of what is really a fantastic smoke.