No, it does not.
Please elaborate: I really can't see the difference between doing a merge (either an easy one or a more diffucult one over multiple files, spread over a couple of days, with intervening changes by others) using either Monticello or Git.
The scalability limits of Monticello are well understood. PackageInfo doesn't scale, at all. You put too many classes in a package, and snapshotting gets really slow. Don't believe me? Make a change in Morphic which has only 200 classes and save it.
You confuse artifacts and models. Give me 1 engineer full time and we fix that.
And it's not like loading is any faster. Seaside takes 10 minutes to build from locally cached [1] packages, only 12 seconds go to running tests [2]. This makes C++ compilation times seem fast by comparison.
[1] http://jenkins.lukas-renggli.ch/job/Seaside%203.1/buildTimeTrend [2] http://jenkins.lukas-renggli.ch/job/Seaside%203.1/lastCompletedBuild/testRep...
Cheers Philippe
Stef