NI MASSIVE

Although this is the smallest UI of any, it's very clear to see what's selected. The whole thing could be bigger - this was pre-scalable UIs, and there's all that wasted space on the RHS - simply widening columns for longer names would be better than nothing. But ux-wise, everything is one click away.
SPECTRASONICS OMNISPHERE

(Deep Tones in Spectrasese, not Sub). Very similar conceptually to Massive, only clearer. 4 user-chosen columns to drill down, all easily visible. For me still the one to beat as the best balance of clarity, functionality and aesthetics.
ARTURIA ARP2600

A totally different technique. Arturia sort of combine their main type and sub type, and you can change from the drop down arrows. I can see I've chosen Sub Bass easily enough (on every patch and again in the search box), but it's quite a bit of wasted space. It's two clicks to change anything - not a disaster, but overall not as helpful as the first two candidates.
U-HE REPRO-5

Another totally different technique. On the small side, but in general this is clear and as quick to use as the first two. I can see what I'm searching for, and it's single click to change (sometimes 2 to clear an existing filter).
NI MASSIVE-X

In terms of sharpness and clarity, arguably the best of the bunch (and imo the prettiest). In terms of information and user interaction, the worst. It's the only one where we can't see what is even being searched for - we just know it's sub. Not bass, because only one field of information is able to be viewed at a time, via a tab system. With sub - okay, we know it's probably bass, but of course with other tags they will span multiple sound types. (Also it's not possible to assign tags to user patches, or quickly reset).
So improvement is needed as NI continue to develop it. They could break out the different fields vertically as per U-he. Or - at the very least - display the selected tags in the massively (!) wide search box, a la Arturia, or maybe underneath each field name display the results the user has chosen. At least then you could literally see what you are looking for.

