As long as you don't mind carrying the weight, I don't see why not. Personally, I use an Abus Granit Extreme 59 U-lock... a bit heavy at nearly 7 pounds, but it's a great lock! The Granit X-Plus 54 (the one I assume you were talking about, since you mentioned level 15) is very nice as well, and weighs either 3.3 or 3.7 pounds depending upon the size.

I haven't used any of the ABUS chains, but would certainly expect them to be of similar quality.