Hey gramps,
Havent driven the Jaguar, but the new Caddilac’s rear seats might be tight and uncomfortable depending on who’s sitting back there. Children might be ok with it, but adults will definately be uncomfortable. I found the trunk to be small too, but that might be because I was shoving luggage. Front seating/cockpit was exceptional compared to recent Caddys. I’m sure the techie in you will be happy.
Winding Road has a review of the two, back to back, in their current May issue: see it online.