I use my grill center (same grill as the 670) quite often, and keep learning new tricks. Things to watch consider:
This thing can get hot. I have rarely used all 8 burners (if you add the sear burner and smoker burner to the 6 main) although it's possible.
Bring a cast iron pan if you have one. They sear great on the side burner, but also make a nice warming option inside over an unlit burner or two. I use a CI Dutch oven as a warmer inside too.
The sear burner, and the two mains on either side, do a great job, but if you are doing steaks consider laying a CI grate on top of the SS grate first, and let it get hot. Makes better grill marks.
I don't use the warming rack often, and there's more usable space if it's not there. I leave it off until late in the cook, if ever.
No issues with hot spots to date on mine. If the grill is new it should not be an issue.
Have an extra tank on hand if you use propane, same for any gasser. Last thing you want is a surprise halfway through.
This thing can hold a lot of food while cooking, so think about where all that food is going to rest when it comes off. Have a table nearby, or a couple runners ready to go.
I have smoked with mine, but only if I have one thing going, which is rare. You might not want everything you are cooking smoked.
If you want to impress, bring a charcoal grill as an option for something. Always fun to manage more than one grill. Some things might work much better on charcoal, and it gives you another option to sear on one and keep warm on the other. People love a guy who can wrangle multiple grills.
Don't forget to light up the knobs. Make sure it has D batteries installed. It is a gimmick for sure, but a cool one!
If the menu calls for something you can rotisserie ahead of time, this grill is one of the best for that. The infrared burner is amazing for a final finish (not used for actual cooking). It can be a little tricky to light.
Can you pay this grill a visit ahead of time, maybe do something simple? Every grill takes time to figure out. This is not your fathers Genesis!
Good luck, and take pics!
Marty