Nope. You aren't thinking right. You don't have to change your entire
platform. Digital signal processing is as sanely possible on Ubuntu as it is
on Gentoo, Slackware, Arch, Debian..err and what have you. The underlying
merits have little to do with anything professional audio, except for (1)
number of relevant packages and (2) quality of those packages. Both criteria
are met by Ubuntu Studio, as well as JackLab and x-popular-audio-distro. Now
if by (2) we mean "stable", 64Studio (as well as x-stable-audio-distro) is
probably the way to go. Stable also means losing out on the latest (not
necessarily the greatest).
Debian? Why waste your time? You've already spent a good amount with its
derivatives. The way I see it - you're not quite sure what you want. You're
assuming benefits. So if you're looking forward to advantages with regards
to music production and audio engineering in general, forget about it. There
are plenty of intelligent power-users and hackers in the more
"user-friendly" software communities; many of them have little time to worry
about "optimising", hence settling on such "easy" platforms for
production.
An operating system does not dictate its user, but the other way around.
Alright, I've preached my share - although only on multimedia-related
advantages. Now if you're a sucker for control, it's a different story. You
no longer base your choice against "digital signal processing", but other
technical merits related to managing and maintaing an OS - which in this
case is a Linux distribution. Here I can recommend Debian, yes, along with
Gentoo and Arch. You do want to go with one that has an "audio community" at
minimum.
On Debian's side, there's nothing to ponder about. You have hundreds of
packages. I would say the same for Gentoo, except that those packages are
source-based. I personally dislike compiling; there is no gain. Arch, on the
other hand, has a small (audio) community (more than enough to get digital
signal processing to work). It has third-party pro audio projects a la
Planet CCRMA or Pro Audio Overlay, both binary- and source-based, and it has
the AUR (a large database of user-contributed source-based packages that are
candidates for offical binary repositories).
Arch sits nicely in between Debian and Gentoo on the technical merits'
scale, though personally I'd say it's unlike either. You install and
configure what you want and get to work immediately. No worries about
compiling, no thinking about -devel packages even if you need to compile,
quick access to a unified build system when you do need to compile
(PKGBUILDs are three times simpler than an ebuild; creating a binary package
is 5 times simpler than producing a DEB or RPM), intelligent community,
and..are the points getting a little excessive? Well, not to worry. Arch has
downsides for your satisfaction too - like no help if you don't help
yourself (I think this is good but many think otherwise). It's an OS for
those who know they want it (I do think you may fit that criteria if you're
honest about "streamlined"). It is early morning here after 5 hours of sleep
and 2 hours before let's-go-down-to-the-office; I just felt like writing (or
typing). Hope this is helpful. Please, enjoy reading ;)
P.S: Bottom line - Thou Shalt Not Switch Distro for Pro Audio Merits Alone
PS2='\[\e[1;31m\]>>\[\e[m\] \[\e[1;37m\]' ..hey no that's not what I
meant
to type :(
Update before sending: Florian above beat me to it, but I'm sending this
anyway for your reading pleasure :) (many smileys for your pleasure too, in
case it's morning)