Depending on what OS you are coming from, it can be a bit fiddly (I had a few issues updating).
You basically need to back up all of your data to SD card, then wipe the internal memory.
I had to wipe the internal memory again after installing the new OS, but once done, I reloaded all my old data and it has been working smoothly since. As long as you have backed up your data, you can always go back to 1.11 (latest official release) if you need to.
It’s currently only the gate/input row numbers 5-8 on the CVIO that work as inputs, and its 0-5v but there are some division/multiplication options that allow you to scale the CV (or you could always put an attenuator in the signal path), but once set up, it works great. Colin has also added CV envelopes to the OS, but I haven’t had the chance to try that yet.