I've been aware of KXStudio for some time. The main (only?) developer, falktx, hangs out on the Linux Musicians forum and is always quick to respond to queries. He's put together the latest audio applications in a form than can be installed on top of various Linux distributions, including Arch and Ubuntu. He's also developed various applications that help to tie it all together and make life easier.
I actually installed KXStudio some time ago when it was released as a stand-alone distribution based on Ubuntu. I played with this for a while, but it didn't seem quite ready back then. I was hearing about lots of new developments recently and wanted to give it another try.
One route was to install Ubuntu Studio first I tried this multiple times, but eventually realised that my old PC just cannot boot from a USB drive of over 2GB, and the ISO was just over that. So I used the 'Net-Boot ISO' method that starts with a tiny image and installs the rest over the internet. That worked fine. I'm installing it as a secondary boot on my only PC as I need to keep the existing system working for use by the rest of the family. This is a slight inconvenience as I have to re-boot to do recording, which takes away some of the spontaneity.
I'm using the XFCE version as a change from my usual KDE and also hope this will improve performance. I'm also using the default theme, which is a little dark for my tastes. I may change that as I find it hard to see some window controls.
One difference from most distributions is that KXStudio generally runs JACK all the time and routes normal system audio through it. Cadence is used rather than QjackCtl to configure JACK, but the options are similar. I still have to find optimal settings, but I was getting low latency and just the occasional xrun.
The main application I've played with so far is Guitarix. This emulates various types of guitar amplifiers and effects. The options are a bit bewildering. There are lots of valve/tube types to select from. I can't say how close it gets to real amplifiers, but it sounds very good to me. There's some good effects too. I particularly like the reverb. I can see me using this a lot for future projects. There's Rakarrak too, but Guitarix looks like it might be better to get a basic guitar tone.
I've also had a play with Ardour version 3. This has lots of new features to explore. The input/output connection matrix is neat and I like the overall view of the track that helps to see where you are. I have a project that needs some MIDI, so I need to check out that aspect.
Anyway, here's the first this I recorded on KXStudio, using Guitarix. I'll report more when I've had more chance to play.
Update: Good write-up of how some of this stuff works from the Linux Musicians forum.