I ended up signing for 88 room nights over a span of 4 nights, with 35 rooms on the heaviest booking night, at the Embassy Suites that was my first pick.
As breakfast and cocktail hour are already included in the room rate, there weren't a whole lot of other amenities to lobby for--- parking or wifi, or a cut off the catering. Since most of the guests will not have cars to park and will have smartphones with 3G/4G, I decided instead to go after a lower contractual obligation (we do not pay a penalty if we fill 75% based on total room nights, so if we have 5 extra rooms on one night and 5 less another night, it's a wash) and "premium" rooms (bigger room or better view, etc) rather than standard rooms. I don't mean to sound selfish but I'd rather have a lower contract target than have 1/3 of my guests get free wi-fi. It's so easy to get Hilton Gold that I'll just send them all promos and they can get free wi-fi that way. The 75% target is a lot more attractive than the 90% they started at, and the 80% they were really stuck on.
I didn't try too hard to negotiate for HHonors points but I did at least get them to agree to give be base + bonus points on anything that I myself paid for, regardless of who sleeps there. Since this is more than Hilton usually gives--- usually they only credit you on the first two rooms you book--- I'm ok with that, as I've got plenty of bonus points right now and will be very short on base points this year, and the Mr and I are already planning to pay for about 8 rooms across various nights (his parents, my mom, and the out-of-town wedding party plus our own).
My next "negotiation" with the hotel will be over the Manager's Reception; if you're not familiar with the chain, Embassy Suites does basically a free happy hour each night for registered guests, and I want to use that as a meet-and-greet time after a rehearsal luncheon, but I'd like to do a very small bit of catering (some properties only serve chips and I'd like to offer some nibbles). If everyone's getting boozed up for free as part of their room rate then there's no need for us to host another cocktail gathering, and it solves the debate over who's supposed to be invited to the rehearsal dinner: rehearse in the daytime, take the wedding party to lunch, then everyone who's invited to the wedding is welcome to mingle for cocktails. Just not sure how to phrase this to the hotel so that they don't try to sell me event space and a bartender
Hilton has set up a standard Event page with a private link, so guests can book themselves, using their own cards, and get our rate (and be counted in our block). I can go in anytime and see who has booked, how many nights, pass special requests through their reservations to the hotel, and run a report, which I'll do about 30 days before our booking drop-dead date, so I can #1 see if we're within our 75% and #2 chase anyone who hasn't booked yet but is needed to push me over. I think the event planner site is more or less a standard offering among the bigger chains.
FWIW booking early was the right thing in my case--- I had been concerned about pricepoint when comparing to the same weekend in 2011, but there is apparently another group at the ES that weekend as it is showing sold out (I can do a Diamond Force if I want), and the online prices on my second choice hotel is about $60/night more than the ES contract.