Hmm... not sure about a lot of things... but CoA's etc. aren't the only tokens being brought in mass to a run. This was my first nightmare run. I didn't have a hardcore build, let alone a nightmare one but both the Paladin and the cleric were very re-assuring and said that everything would be fine.
One of the things that made me feel better was that everyone was going to get a RoH and a Charm of Synergy (+1 hp per CoS in the group).
After I showed my build to the coach, I was allowed to take my cart-full of tokens to the coat check. I only took my weapons and consumables with me. I have ben playing TD since 2013 (I missed playing TD in 2014) and this is the first time I have heard of having to take tokens with me. I specifically asked my coach if it was okay for me to take all of my other tokens back to the coat check and he said it would be okay since I had the excel spreadsheet to track my situational tokens.
As I said, I was on Nightmare level. In the final room with the Beholder (Combat Run), our Dwarven Fighter used his taunt ability. The most damage he ever took was 32 pts, not 50. We didn't kill it but were chased off by his minions. We did 457 pts of damage. When we asked how many hp the beholder had, he told us 600!! That's when I knew I was going to have to use something better than a +1 Silver Bastard Sword at the next GenCon.
In the first combat room, the DM said that there had been a meeting that morning and that they had decided that anytime a token came out of the puck, it was an automatic miss. When we pointed this out to the other combat DMs, they said that was the first that they had heard of it and when a token came out of the puck, they put it back in and went from there.
I got lucky, my group didn't experience any of the bad DMs that all of you mentioned. We did however get to see a group (the combat group that was before ours) told by a volunteer that shouldn't be using treasure enhancing tokens that weren't theirs. She told them that they were getting taken and to be more careful next time. No idea what the actual arrangements were but my brother told me of one fellow who showed him a huge amount of tokens (well over 100) that he had gotten through brokering treasure enhancing tokens with people.
I was a little embarrassed by the fact that only one other person in my group did NOT have a CoA besides me. I do not consider myself to be an elite player but are CoAs really that common? I have been more worried about surviving that anything else. When I was at WYC, I was one of only three players to leave the last room alive. I killed the monster in the last room with a lucky slide onto the 20 spot when I had only 2 hp left!!! I was bound and determined that would not happen at gencon. I had a much better build for gencon only to find myself totally outclassed by everyone in the group except for one player who was doing his very first run (and he was using tokens from the dwarven fighter who was loaning him things like a +3 Deathcleaver).
@the original poster I can see why you would think you were getting a raw deal from the DMs. Based on my experiences with DMs, I think you probably experienced lazy DMs, not ones born of malice.
@everyone else I do agree that things need to be much more consistent on TD runs.
As to loaning tokens... while I can see why people do this, TD players are generous to a fault, I think its a bad idea. Much as I liked having 10 extra hp on my first Nightmare run, looking back I think it just cheapens the game. Players should be able to take pride in their builds but you can't really do that if some of the key tokens aren't yours. Succeed or fail, no one should be allowed to use a "loaner" token. Yeah its cool the first time you get 7 extra treasure pulls (like happened to me once) but I didn't earn them, so it shouldn't have been allowed. Same is true with those 10 extra hp. Or the extra level that the loaner RoH gave me.
Whether or not disallowing loaners can be enforced or not is another issue entirely. Given the nature of TD players though, I think that most of us try to obey the rules and would stop loaning them out IF Jeff said we couldn't loan them out anymore.