Change Management/Source Control

I am moving from Proworx32 to Unity as PLC programming environment, but Unity does not include any source control/change management, so I am looking for other products to supplement Unity.

1. MDT Software - AutoSave - Does anyone have experience with this product or have any similar suggestions.

2. Source Safe - seems obsolete?

3. Sourcegear - Vault - looks like a robust system, but for generic source, not specifically PLC programs.

4. Asset Center - Rockwell - This product seems to be very comprehesive in support and PLC network aware, but maybe only for AB products.

Any thoughts?
GBrown