Well. I don't really mind dispensers, but I'm all for no sentries and teleporters. Sentry for obvious reasons, and teleporter for a few different reasons.
1. I've seen people build teles from spawn straight to the end of the surf map, now if you think about it, there is likely some sort of orb at the end of the map, which gives you buffs, anything from a moving dispenser to invincibility. Now that being said, I feel like teles make that extremely unfair considering they didn't do anything to even get there and then they are just getting a buff that they can walk into arena with and kill everyone in there.
2. What supreme said, if you REALLY want to teleport somewhere, use !cpsave and !cptele.
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On the side of dispensers, like I said, I don't have a problem with them as long as people aren't blocking areas with them.