i have to say my experience is quite different. % uname -aLinux pensomolto 3.0.0-12-generic #20-Ubuntu SMP Fri Oct 7 14:50:42 UTC 2011 i686 i686 i386 GNU/Linux ubuntu 11.10 but note that i use gnome not unity (because i want to use it).
i use 9vx, and have done for years. i use it as both a development environment and a cross-development environment. since i fixed the direction flag bug (which should be in the hg copy) it has been just fine on my system. in fact, i use a fairly old version of russ's with that change, and one other small change, no others that i know. it runs at least for weeks, with fairly solid work during that time, all day. the plan 9 files are in the linux file system. usually linux packs up somehow before 9vx. my only practical problem so far is DNS, which i suppose must be single-threaded. ugh.
