In my opinion, the deciding factor between those two is the depth. The FP is "counter depth" with a depth of around 27.5 - 28". Which means that part of the fridge will stick out beyond your cabinets.
The Liebherrs on the other hand are true counter depth. It can be completely flush with your surrounding cabinetry. This is a higher end look, so you gotta pay! :) It's also possible to get custom panels on the Liebherr.

Also, I believe the Liebherr has dual compressors, but the FP doesn't. I'm not positive about that though. I have read that the Liebherrs with the BioFresh feature keep food amazingly fresh. I have no first hand knowledge to the degree of truth there.

AineLaine is correct. The Liebherr can be built in so they look different from the F&P. They are also much taller. I have the 30" and it is about 8yrs old. I love it. Mine can accept panels.
Good luck!

The others are correct, you are not comparing apples to apples. Lieberr is fully integrated and can be set flush with surrounding cabinetry, even inset. You would need to compare to other fully integrated units, such as the Sub Zero.
I have the 30" Liebherr with bio fresh, and absolutely love it! Integrates perfectly with my cabinets, super quiet, keeps produce fresh extremely long, and makes really cool little clear ice cubes :) Chris

Apologies for resurrecting an old thread, but elisamaria - what did you choose? I am facing the same decision - either 31" Fisher & Paykel RF170ADX4N ($2000) or 30" Liebherr CBS1660 ($3500). I don't mind the depth difference and don't care too much about the high-end built in look. I just want counter depth and ~30" because my kitchen is a tiny 8'10" long galley. I think the Liebherr looks a little simple and felt a bit cheap in the store, but I also know it's supposed to be the better brand and I think it has almost a zero clearance hinge, which is very appealing (don't have to build in as much space between fridge and wall for clearance). But are those features worth an extra $1500?

Fisher & Paykel

Liebherr