Expect a ton of people. A place that is extremely crowded, and you may wait up to 2 hours in lines (B****m Booth). meeting the pro's or big names in the industry comes with a very long wait. Every year you get less samples from booths. Every year it gets busier. Friday early and Sunday late are the best times to go. Saturday is the busiest day of it all where you will be shoulder to shoulder and may take you 20-30 minutes just to walk across the venue.
CP will have a booth, and they usually do a lift and get together. There is a lot to do aound the city even before and after the expo. Definitely check it out. Not to mention plenty of other events going on during the arnold while the expo is going on (Strongman, powerlifting) etc.. So there is something for everyone there.
not to mention if you actually attend the pro show which is a great experience.