I worked at Microsoft before and after my team (not Windows) did the Source Depot -> git transition, and I can say that it was mostly for the better. Source Depot was pretty good as non-distributed VCSs go, but it doesn't hold a candle to git. Some specifics:
- Branching in SD sucked, the only way to work on multiple features at once was to either have multiple copies of the repo or constantly fiddle with "package files" that contained your changes, and the whole thing shit the bed if the server went down.
- All the new hires both from college and the industry all know git and there were an increasing number of them who just found it bizarre that Microsoft was still on a proprietary, non-distributed system.
- Higher-ups (correctly, IMO) decided that VSTS/TFS had to have git in order to remain competitive, and that we should be eating our own dogfood. That's partly a marketing concern but also a legitimate technical decision.
- Branching in SD sucked, the only way to work on multiple features at once was to either have multiple copies of the repo or constantly fiddle with "package files" that contained your changes, and the whole thing shit the bed if the server went down.
- All the new hires both from college and the industry all know git and there were an increasing number of them who just found it bizarre that Microsoft was still on a proprietary, non-distributed system.
- Higher-ups (correctly, IMO) decided that VSTS/TFS had to have git in order to remain competitive, and that we should be eating our own dogfood. That's partly a marketing concern but also a legitimate technical decision.