I have not ridden a Liege 75, it looks great though.
However, I am the owner of a Kendo Phantom, which is from a small brand in Taiwan (see here: https://www.facebook.com/42807650726361 ... 54/?type=3
I picked it up while on a business trip to Taipei. The Kendo Phantom is made in the same factory in Taiwan as the Merckx Liege 75, uses the exact geometry and same tubing (Columbus Zona). The only differences I can spot of my Kendo to the Merckx is a tapered head tube and a generic Taiwan or Chinese-made carbon fork (the Merckx appears to use a straight steerer) and perhaps some subtle differences to tube profiles. The Kendo can only fit 25mm tires as well.
How it rides: I've only tried a handful of steel bikes, including my own 18' Ritchey Road Logic. I found my Ritchey to have a livelier feel than the Kendo thanks to the Ritchey's lighter weight. Rear-end stiffness feels about the same. The Kendo feels slightly more sluggish than the Ritchey but more solid going over bumps. It excels at providing comfort, especially with its tall headtube. Again, this may not represent the Merckx due to subtle differences between the Kendo and Merckx. I'm light and like to spend a lot of time with my head down, hammering or sprinting. I can attest to the Ritchey because I own other carbon bikes (BMC SLR01, Look 595) and I enjoy the ride quality of the Ritchey and put an equal amount of time on it as my carbons. I probably won't say the same for the Columbus Zona Kendo. If you are looking for comfort, my guess is the Merckx will suit you. If you are looking to ride aggressively, something else might be better.