I think you're right in this opinion.
I've marched in the Alamodome; it's different, but not bad. I think everyone that hasn't marched there before is gonna have a blast, and it'll be an experience you never forget. If there's one piece of advice I have, it's to not leave anything out there questionable. Don't walk off that field saying "that wasn't my best". Even if it's prelims, make it the best; you may not get another chance...
Remember, it's all about what five people think of your product that day. They don't care that you vomited at rehearsal last thursday. They don't care that you lost a girlfriend or two due to marching. They don't care if you've spent 100+ hours rehearsing.
You all just gotta show them that YOU deserve the highest rank.