BMW Turbo and 'reliability' do not typically occupy the same paragraph in a positive manner. I know several people who make a great living patching them back together, and everyone I know who's owned one, stopped at one (and I'm not even counting my personal experience with a Mini Cooper since it was a Peugeot engine at the time).
I'm no Toyota fan boy, but can't imagine choosing a new/off brand with BMW power over house brand Toyota/Lexus.
Looking under the Grenadier, it looks an awful lot like a JL...so I have to wonder why you'd choose the IG over a Jeep, aside from aesthetics and wanting to be the life of the party as someone earlier noted. The GX550 sure looks like a cool offering for todays market if you're into new vehicles.