Ardour Ardour 3

No issues.

PERFORMANCE

No special remarks

OVERALL OPINION

Very good computer music software, available for most Linux distributions (Ubuntu, Ubuntu studio, Debian...). Very powerful! Besides, it's free software.

To install it you have to download a script. The script checks that your system has everything it needs to run, especially Jackd2, and then installs the software within a minute.
(Update from May 2014: You can also install it via the package manager on Debian Jessie or Ubuntu 14.04 and similar)
The overall setup is quite easy.
I haven't found any incompatibilities.
The manual is just like the software itself: Clear and precise.

PERFORMANCE

I use it with a Casawave PC and they work perfectly together: Core i5 3570, 8gb ram, 2 HDDs at 7200 rpm, Antec housing, etc.
Soundcard: Focusrite 2i4.
I have Jackd2 (the wonderful audio/midi manager) set to 2.6 ms, 44100 and 32 bits. You can do that by activating the real-time priority when installing jackd2 and qjackctl and adding (as root) the line @audio - rtprio 95 to the /etc/security/limits.conf file and then adding the name of the user to the audio group: sudo adduser user audio... logout/login and you're good to go.
The software works impeccably with this setup, it's very stable.

OVERALL OPINION

I've been using it since the stable version came out (May 2013). I'm now on Linux but used to use Adobe Audition 1.5 (then 3) and Cockos Reaper 3 and 4 under Windows. I chose Linux due to its stability and the quality of the software included: If it works, it works well all the time, you won't get any unexpected crashes after two months, no blue screens, and no prohibitive prices.
Contrary to what the urban legend says, I don't spend too much time fiddling around with my Linux setup, I make music.
Ardour 3 is very well thought-out, the workflow is sober but pleasant and the software is very powerful. Audio editing is very comprehensive and precise. There are lots of keyboard shortcuts available. A bonus on version 3 is the Smart tool, like on Pro Tools, which changes automatically the editing function (selection/region/zoom/fade) depending on the place of the mouse on the region: It's very quick and clever. The mixing tools are easy to use, the interface has a clear and simple interface. It features everything you need to work seriously: Pre- and post-fader plug-ins, automation.
What I like best:
- Its clarity: No abstruse submenus, no toyish functions, a no-frills interface (without a "vintage console" or "cockpit" look) with a design conceived to make work easier.
- Regular updates (for registered users/contributors) that really bring something new (for example: The addition of more pro VU-meters, a new and clearer design of automation curves).
What I like least:
- At first, you'll have a hard time with Ladspa or lv2 plug-ins. Bye-bye VST and the like, but there are serious alternatives available: Calf audio, Invada, linuxdsp, mixbus plugins, CMT, TAP, etc... Although they are not proper to Ardour.
Excellent value for money. No iLok, no dongles, no serial numbers.
I recommend it highly.