Our office is running VW11.0.1 with no problems.
We did install 11.5 on a couple of PC's, but have reverted back to 11.0.1 due to stability problems. After using 11.5 for a while, I can say that there are no major improvements that will make you more productive than using 11.
We also like to keep up to date, but are waiting for further maintenance releases of V12 to come out.
BG
VWA11.0.1 WinXP