1. ardour3 is is still in alpha status. things may not work.
2. upstream hates the thought of distributors packaging ardour to begin with (even though gentoo ebuilds just fetch and compile the source), but they especially do not want to see the alphas and betas officially packaged. this is an unofficial ebuild, in an unofficial overlay. so please, don’t even think that this will make it into portage until ardour3 has had a stable release. i don’t maintain the official versions in portage, anyway.
3. upstream requests that you do not bug them about problems building ardour, running it, etc. do not hit their forums asking for help. instead, if you need to troubleshoot issues or offer patches and workarounds, visit #ardour on irc.freenode.net, or visit their mailing lists. this same warning is repeated in my ebuild, just to make sure you know that you’re agreeing to play by these rules while you try out ardour.
4. a much friendlier community of folks willing to help can be found at #opensourcemusicians on irc.freenode.net. many of ‘em have been using ardour3 for awhile, and are familiar with the latest code diffs and how things work compared to ardour2.
5. as with any ebuild in any overlay, if you have issues, first contact the maintainer of the overlay (me), rather than risk wasting anyone else’s time. that being said, i’ve been making music with ardour3 for almost a month now, and aside from UI quirks, find it pretty stable. support for linux VSTs is definitely a plus, as is the inclusion of basic MIDI sequencing.
if you want to try it out, you know where to find it.