Agreed. I invested in a Keylab MKII, a Minilab MKII and the V Collection, mainly because of how the controller mappings worked with Analog Lab 4.
In Analog Lab 4, you have up to 16 synth parameters pre-mapped and you can change the assignments of them all.
In AL V, we've got a mere 4 (!) synth parameters.
The rest is f/x and mixing related, stuff I way prefer to deal with in my DAW.
I don't get Arturias rationale behind this. In Analog Lab 4, you have the option to use "Live mode", which is very, very similar to what is now the only available mapping mode. Why not have both options still available?
The Keylab MKII even has a dedicated button to take you in to Live mode, which is now rendered pointless, since it's the only available mode. And speaking of pointless, the printed text on the Keylab MKII:s synth control section is pretty pointless as well now, since it no longer corresponds to the parameters you're controlling.
(Not at all a fan of the GUI changes either, but maybe that's mainly down to habit.)