As the previous owner of that motor, I wouldnt do to much to it and just run it as it only had 170k km but obvious bias!
I'll likely cruise out to your neck of the woods some time in the next year (buddy lives there) so when I'm around I'll ping ya if you want to give the LS a spin.
As one of the crew who has actually owned and driven both sides, the only space I'd say is a serious large improvement is in fast freeway flying, and even that is only an improvement because I swapped the trans at the same time so I have a much taller high end w/ the torque to move it. I took that motor out to CO and went over all the passes and whatnot, it wasnt fast but it never gave me any sort of issue. A troopy was never made to have 400+ hp/tq, and realistically none of us ever actually need that. I did my swap primarily because it seemed like a fun idea and it has been, but anyone who says its "practical" is lying to themselves.
Long term reliability I'd say is a wash, both are reliable, parts are a bit easier to get from the LS in the states, but its not hard to get parts for the toyota motor in my experience? You're just talking a chance of picking up same day vs needing to get it shipped almost always. Truthfully I dont think 95% of us abuse or use these things so much that other reliability concerns are top need
IMO if you havent lived with a troopy yet, throw the motor back in and try it for a bit. After you've used it you'll know what you want to do. I got mine from someone who was in love with the IDEA of a troopy, and realized in practice they're kinda dumb. A lot of us just happen to like that kinda dumb