Okay, so I actually played it now.
- Lv 3 dispensers have ~ 1/3 more health than the usual dispenser (takes 4 hits with wrench, regular takes, but almost dies from 2, so a little over 1/3, but not fully 50% more). They give health at twice the speed. Gives you metal in 60s, not 40s, and also refills 1.5 times as fast. Can hold 1.5 times as much.
- Lv 3 teleporters. You can uprade either entrance or exit. If you upgrade one, the other is also upgraded. If one is killed, the other goes down to lv 1. Cooldown is around 2/3 of the time on lv 3 (maybe half), and it can take ~ twice the damage.
- Stickies can get killed by any shotgun/minigun, but not by rockets/melee weapons. They do not explode, but rather just get destroyed, leaving nothing. Have ~ 10hp each.
- Some small changes on the maps. Dustbowl for instance has taken away an entire place to attack from, and nerfed another one (but made it more demoman friendly).
http://www.vgchartz.com/games/userreviewdisp.php?id=261
That is VGChartz LONGEST review. And it's NOT Cute Kitten DS
