OSS Enthux on my side
To be part of a hybrid environment were MS Technology enthusiasts and OSS/Linux gurus merge is bit hard. Some times you'll heard "Meron na nyan samin before MS introduced that" or "Ano ba yan gaya-gaya". But its good to me, though sometimes bit intimidating. I know there realy is a competiion even we're in the same organization.
On the other side, most are benefits to me. First, i've get bit acquainted with OSS tools, like log4net, nunit, ndoc, nhibernate, nant, etc.. Look for the "N", most tools ported from java and are proven technologies. Its a nice experience also seing a technologies/projects with Java, EJB, Struts, Spring, Linux, IPTables, Hibernate etc.... Yaiksss, ive got terms overload.