Axpona

Looking for feedback on the AXPONA event in Chicago in April. I have never attended an event like this.  Is it a worthwhile event if you are looking to make some upgrades to your system?  Are you able to make purchases at the event or do you order and product is shipped to you?  I also noticed that some brands like Wilson, Kharma, Transparent, Shunyata or not on the list and if there is any reason why?  

Any guidance or feedback is appreciated about attending something like this is appreciated.