The lightweight Linux desktop environments have been battling for years now over who's Windows 95 clone is better. It's a nice paradigm because it's familiar to many users and serves its purpose. However, does low resource usage necessarily imply lack of innovation regarding user experience? Or does familiarity in this space just trump other concerns and experimentation should be left to the fat environments like Gno…
Check out Elementary OS - Ubuntu with the DE rewritten in Vala with design as priority: http://elementaryos.org/
IMHO I've used buggy software that happens to be written in Vala, but I wouldn't say it is because of the language.