Load-in/load out was also always very well-run and smooth; Gen Con is a huge show and Indianapolis has hosted it for many years, so they have the system down pat. Communication is good with multiple emails being sent out in the months leading up to the show, and staff was always pretty responsive to any questions I had.
Downside: it's an expensive con. I'm local, so I only had table cost and parking, although even that can be very pricey. During the years I went, a 2 panel table was about $300 and a 4 panel table was around $400. I believe that has increased to about $400/500+ now. With the table cost comes 2 Exhibitor badges, access to the Artist/Exhibitor hotel block, and 6' wide table with either 2 or 4 cloth panel walls behind you and 2 chairs. Wi-fi and electricity cost extra – and the Convention Center prices are steep. However, downtown Indy generally has good reception so you shouldn't have any trouble processing cards even if you don't pay for Wi-fi.
(I should probably note that the grid cube table displays you often see in Artist Alleys are never seen at Gen Con, and I'm not sure they're allowed.)
The Exhibitor hotel block is important, as hotels downtown are very expensive for the weekend (I hear average prices of $1000-1200+) and often sell out immediately. If you're trying to save money I recommend getting a hotel further out from downtown and driving in. There are stations of rental electric cars around the city, so you don't necessarily need a car of your own, even if you're not downtown. If you do drive in, parking averages $20-25 for a day, although there are some $10-15 options around if you are willing to walk a bit or get there early.
Food options are very good. There are plenty of restaurants and a ton of food trucks nearby, including some gf/vegan options if you have dietary restrictions. The convention center itself has a cafe and some basic concessions within it, and while it's not amazing fare it's serviceable and not too marked up.
Now- the "if you can get in" part. Since 2015, Gen Con moved to a fully juried system for applications. There is a non-refundable $25 application fee. You submit 3 images and an extremely short description of your work. Since this system started, the range of art styles that get accepted has been rather limited. If you're not doing realistic/mainstream style fantasy artwork (think Magic the Gathering or D&D) it seems that you have a much harder time getting accepted. Also, only 2D work is allowed; no ceramics, crafts, or jewelry.
On the whole, I absolutely recommend it if you can get in – I usually made about 3x-4x my costs back, and if you are interested in doing work for games, there are a lot of game companies there who sometimes scout artists from the Art Show. I got several job offers myself from my presence there. Especially if you do original or high fantasy work, it's worth the attempt to get in. May not be as good for more anime-styled, comic book, or fanartists.
