The first thing to understand about Keyscape is that it's nothing like Omnisphere 2 (or even 1) in terms of programmability and depth - that's simply not the idea behind it.
While Omnisphere gives you an expansive range of editable parameters and synthesis engines to delve into, Keyscape is all about the sampled instruments themselves, rather than the comprehensive tweaking of them.
However, Omnisphere 2 owners can actually load Keyscape presets into said synth, bringing its arsenal of sound-shaping and processing weaponry to bear on Keyscape's vintage tones. All that's required to do this is the latest version of Omnisphere 2, which makes Keyscape's presets available in its browser and loads them in as layers, complete with all their controls. That's a very big bonus, for sure.
Keyscape's interface is clean and straightforward: patch browser on the left; big picture of the loaded keyboard in the middle (sadly not mouse-playable); tabbed sound editing, Settings and Info (revealing the history of the current keyboard) section at the bottom; and Utility and System menus at the top.
The browser lets you select from the ten top-level instrument types in the top pane (Acoustic Pianos, Clavinets, Electric Pianos, etc), or head straight to one of the 36 specific models in the dropdown menu below. The presets are listed in the bottom pane, and with over 500 included, most of them come in related sets, so 'Rhodes - Classic Amp' is followed by 'Rhodes - Classic Amp Warm Blues', 'Rhodes - Classic Amp Clean Dry', etc.
Loading a preset takes a while with many of the instruments, even from SSD, as you'd expect, given their scale. The text 'Preview ready' appears in the progress bar when the patch is available for basic (ie, without round-robins and the full stack of velocity layers loaded) auditioning onscreen or via an attached keyboard, though, which shortens the thumb-twiddling time a bit.
Keyscape is almost impossible not to fall in love with. The care, attention to sonic detail and passion that have been poured into it are palpable at every turn, the huge preset library is an absolute pleasure to wander through, and the deep multisampling employed results in a very high level of playability.
As its almost self-conscious ease of use suggests, it's very much a 'player's instrument', and the sizeable sector of its target market who consider themselves keyboardists first and 'producers' second will really appreciate the almost instant nature of its architecture, quite aside from its stunning sound.