How are bindings supposed to fit??

Ok, I have in my possession two pairs of 2007 LF Sphynx bindings. One is a size 9-10, and one is a size 10-11. My shoe size is leaning towards a 10. I've never had a pair of bindings that actually fit me, so I ask this question: How exactly should these fresh, not broken-in boots feel on my feet right now? Should there be absolutely no extra room in the boot (the 9-10s seem to almost have too little room, and there is a small amount in the 10-11s)? Help is extremely appreciated.

LF bindings tend to be a little narrow. Contrarily, I have kind of wide feet and wear LFs. I wear a size 12 shoe and wear the 10-11 shanes. I like to get my bindings tight so that they will have room to stretch. For about the first 5 to 10 rides my feet cramped a little, but it slowly went away due to the stretching out of the bindings. I had an old pair of CWBs that fit really nicely when not broken in...after about a half a season of riding, they were way too big. I would go with the size 9-10.