The ideal comparison would be to run the exact same experiment on the exact same hardware on .net and see how it compares (ie, run Xamarin Studio on .net, open and build Xamarin Studio). But I would be interested in any quantitative comparison of Mono and .NET GC performance.

Basically it's not obvious to me if this GC improvement widens Mono's lead over .net GC performance, brings Mono close to matching .net's lead, or brings Mono from terrible to merely bad in comparison to .net.