Right now I use the 0.5.8, so it's still alpha, and what I am writing is alpha, too! :-).
Felicia is still working on basics of the program, but she is open for reports and discussion, and she did a really good job on stabilizing the software during the last weeks.
As for me, basic handling is simple, but the more advanced options are a bit hidden, one needs to play and click the options to discover the possibilities of customization. But, even now this tool is magic and for everyone using NIs Komplete Kontrol a must have! Run it, and before long you have a lot more of presets to choose from in KK! Invest a little more time for your favorite plugins, create NKS specials, add patch directories - and you do not have to jump from one VSTi to the next one to find what your looking for, because you will find everything in KK.
Of course and because it's alpha, it needs additional work and time. But I was wishfully waiting for NI to add such a helpful feature to KK which really saves me hours! Hence 5 stars in advance for the finished product.
Just bought that, sounds promising... crashes on scanning the plugin dirs, crashes on loading the plugin maps, crashes on selecting a patch (on a WIN 7 x64).... Wrote to support, let's wait and see.
EDIT: the nice guys @ (whereever I had bought it some months ago) gave back the money since I was not able to make it work... last week I bought a CODE25, so I got VIP3.1 for free... updating to 3.1.1... it still sucks! The Standalone stops scanning, offers a window to report a bug, and on sending the report it says, that sending the report failed! Opening the VIP plugin in Reaper, 2 clicks on the plugins GUI, and Reaper crashes... do not buy.
If you're looking for a an exhaustive reaper review, read the free manual... ;-) ... my two cents ... I've been working intensively with Cubase for years getting bugged more and more of its restrictions and clumsiness. A year ago I switched to reaper... it was like moving from a stumble-upon-on-entering-lumber-room to a catch-a-breath-meadow. It does not waste your time when loading large projects, neither huge numbers nor sloppy coded VSTs bring it to it's knees, and there are much more things to enjoy. Of course it's not perfect, using such a mighty tool one discovers many things to improve (e.g. the thing is getting crowded and confusing with functions, devs should focus on structure). But as far as I've been using it it supports me, and doing things in Reaper I haven't done before is a question of learning and not about constructing workarounds.
Back to my starting point... some months ago I bought the Cubase 8 Upgrade... setting the VST directories I got an error message, that one of the VSTs is corrupt... and Cubase stopped reading and initializing my VST collection. None of my VSTs was available inside of Cubase... emails to Steinberg... digging for logs... Reaper just told me, that there's a corrupt VSTi it would not add to the FX list... all my VSTs were available (except for the corrupt one). A single simple example, but its exemplary for what is featuring Reaper. Using Reaper the complexity of your working is your decision, and not a coercion of your DAW.