I have all the versions listed above, plus TS2009 which although I have registered the serial stubbornly refuses to appear in my listed versions. I still use TRS2004 and TRS2006 on a laptop with the Intel integrated graphics chip because they both run acceptably on it. My main work at the moment is using TS2010 on a much higher-spec laptop to develop the EKLR, which I will probably then migrate to TS2012 once T:ANE gets superseded by whatever is on the far side of the tunnel. By which you can probably guess that I prefer to live on the maimed stump rather than the bleeding edge. Edit: I just watched half of a video by Squirrel on Youtube, and provided my Medion Erazer laptop meets the spec for T:ANE, I expect I'll be getting it rather sooner than I initially predicted.
I also like using TRS2004 to make model railway layouts from the plans which have appeared over the years in magazines but for which I do not have the room-space available. It does this with effortless ease, since Surveyor is, to my mind, the best building tool around, and since it is a model railway I'm not bothered by the low-spec physics and steam effects. I tried upgrading to TS2012 a couple of years ago but stopped when I realised I was spending more time trying to solve content-faults than I was in actually running the trains.
Something I have noticed over the past twenty or more years as a software developer is that the world is split quite distinctly into those who demand the new, and those who like the comfort of things that they have learned and assimilated into their lives. The former can be epitomised by the swipers of touch-screen phones, the latter by those stubbornly clinging to clamshells with buttons. But then, whilst everybody else was beavering away on C# or C++ on quad-core machines, I was happy using Fortran and Macro11 on P4s and PDP11s.