I think the GL-Class is pretty nice looking actually. It's rather conservatively styled but still comes across as elegant, and somewhat tough. The M-Class interior doesn't bother me, it looks nice and the materials are decent and ensure you feel like you're sitting in a premium vehicle.

The GL-Class has several advantages here IMO:

1) Permanent 4WD (4Matic): the Escalade will come with an optional RWD version, which means buyers who opt for this won't take it offroad. And while it's hardly any different with the GL-Class when you think about it, the added benefit of permanent 4Matic might have psycological advantages for some buyers. I also feel that the GL will be better offroad. I don't think the Cadillac was even designed to go offroad (correct me if I am wrong).

2) 7Gtronic automatic transmission: improved acceleration and fuel economy as well as midrange performance. Will make the most out of the engine, which I don't think is underpowered at all. Besides, there's bound to be a GL550...

Either way, I wouldn't even consider the Escalada because it lacks a more practical engine. The GL-Class in Europe will come with the excellent 3.0 V6 CDI diesel, which would be my choice. Screw the V8's!