I have finally managed to play AUF yesterday and it was quite nice, to be honest. You have to work as a team or else you're screwed (so you have to hope your team knows what a team is...)
I have a question, though: what's the weapon progression? I noticed you jumped from a DD44 or a PP7 to a D5K and soon you'd have an AR33 in your hands. Isn't that a bit drastic? The matches end quickly and if the key player manages to score a couple of kills, his team will be armed with some serious firepower pretty quickly (especially considering the fact he other team may be a level or more below - an AR33 is serious firepower against almost any other weapon).
Does this progression also depend on the number of players? As in, the more people that are playing, the smoother is the progression, and vice-versa?
I just felt it needed a smoother weapon progression for it to be more enjoyable. The matches ended pretty quickly, anyway, and we weren't many in the server (teams of four at the time) and the map in question had tight corridors where all the shooting took place so it was easy to funnel everyone into a trap and make an easy killing. I felt the mode needed longer matches, but maybe that's just me and I love playing in teams so I always want team matches to last longer (and the rounds as well).
This smoother weapon progression could also help when the key player is left alone: he only has a shotgun to fend off the enemy team and they may be armed well (or too well) and that is practically game over for him. Sure, you can engage the turbo and bail out but 3 or 4 guys shooting at you will end your run pretty quickly, especially if the map's hard to navigate at a high-speed (a map with many corridors, handrails, stairs, etc.)