The third and second row collapse though headroom is a little less because of the stadium seating, though not any less than the Cherokee with the blasted spare tire.
I find it's not as big as it looks, but perhaps that's the benefit of the 5.7 putting out enough power to move it properly.
When we were looking at them I had my wife drive the JK Wrangler with the 6 cylinder. She complained it was weak.
Then we drove the Commander and she contemplated getting it with the 6 cylinder (she test drove the 5.7) so I reminded her of the drive in the Wrangler and her comment. Then reminded her the Commander was another 2000 pounds over the Wrangler. There are many ways to get a Hemi sold to your wife. That way worked very well for me. Can't imagine the Commander with a 6 cylinder...must suck.
We took it on trails and with the Quad II Low Range/Electronic LSD it's unstoppable. If I were going to run trails with it regularly I would ditch the chin spoiler and mud flaps, put a lift on it, and probably put rocker armor and real bumpers on it, not to mention a 12.5K winch. AEV's Iceland version comes to mind. But I gotta send two boys to college before we do something like
that...

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Of course there's always the Startech version... (blech!)