The ambassador is a fine weapon but for my purposes it does not help me "reliably" when a scout or pyro are up close and on me. The point of dr spycicle revolver is to be able to do damage fast, give information on the enemy uber percentage/sniper location, and also survive. A good example would be finding out the enemy medic has 90 percent uber, calling it out, and then engaging on the medic. Notice there is no time to line up my shot in this scenario, rather my goal is to shoot the med a few times, bring the heavies attention onto me and allow a jumper to have a better shot at dropping the med. The revolver is much better in fast paced situations where you make a call and you go with it while the ambassador is better for situations where you get the headshot and then you tell your team to push.

I mentioned survival as well and the revolver when running away from a pyro or scout does not need to kill those individuals to be effective. For instance putting one or two shots long range on a scout as he is pursuing you will deter him from rushing in giving you enough time to perhaps charge your dead ringer or find cover where you can keep him at distance, poking your head out to put out one of those damaging 40- 60 damage shots on the scout. It is much easier to land a bodyshot with a faster and more damaging item then the ambassador so the revolver deters better leading to better survivability, allowing you to be involved a greater percentage of the time in team fights where the revolver shines as a clean-up item. In addition if the pursuing enemies overextend because they think you are weak as a spy, you can take down a pyro or scout before the team fight and give your team an excellent advantage where as an ambassador would have less of a chance of doing this.