7th Edition has been with us for a while now (8th Edition is probably not too far off.

NagoyaHammer, as an event is a little restrictive, mainly to help games run smoothly, quickly and provide an environment where everyone can have fun and knows what to expect.
Similarly, when playing at someone's home players are free to organise whatever style or type of game they want. Of course, you can do this at Joshin as well, but with the time constraints and other games going on, it's sometimes easier to just bring along your standard army and slug it out with a minimum of negotiation.
At games since 7th dropped I've seen a lot of stuff on the tables that made me think 'I'd rather not play that without some warning.' Multiple fliers, armies of nothing but tanks, massive super heavies and so forth. Don't get me wrong, I can field all that and more (compulsive obsessive purchasing can be good at times), but it's not something I would have usually planned to bring along myself.
So, after all that waffle, we get to my point. What do you consider fair game in a standard pick-up game? What do you think merits giving your opponent a heads up about your list first? What is an average size game and what points level do you build your army towards? Multiple detachments/formations are acceptable or should players come along expecting to play against just one?
I'm not aiming to limit what people use, I would just like to get an idea on what everyone considers a 'usual' game is.
Thanks for reading.
P.