Didn't realize that was an accident, but I always thought that Valve should change the cost of the dispenser to 70 and the mini to 110. Gunslinger engies aren't team players the way they work right now; they're just straight-up area-denial offense. It would be nice if they reduced the firing speed and greatly reduced the range of the minis, as well. They should not be more effective than a level one sentry.
Actually they serve a great purpose to the team.
The point of the gunslinger engi is for the engi to place down his tele's, maybe a dispenser somewhere near the objective, and join the battle himself instead of sitting around repairing things. It's a fast acting sorta thing for mainly offensive purposes as well.
If your on Blu Team, on a payload map, or a cp map, chances are, you won't have enough time to build up a level 3 and still be able to be apart of the major combat area.
The best loadout I can possibly give personally with the gunslinger is:
-Gunslinger: Because you know...part of the set for a purpose...
-Widowmaker: Refills ammo for you as long as you have a good shot.
-Short Circuit: Stops oncoming projectiles long enough for your mini-sentry to get built
It's not a bad class, and I use it a lot when playing offensive engi.