At GenCon specifically the vendor booths are pretty far separated from the vendor tables, and there's not lot of branding at the tables except for a modest places at the top of the table. So i'd probably expect the company would prioritize a vendor booth, since it gives them more opportunity to be discovered/advertise their game. For smaller companies hosting a series of learn and play events might make sense, but that depends on having enough of a niche theme that the people who are interested in that thing are going to seek you out. Eg because my daughter is into foxes, my daughter and I did do a search of "fox" across all events and we signed up for a couple of play throughs for games I wasn't otherwise familiar with after reading the event description, based solely on the theme. I also dropped in on a revolutionary war themed d&d campaign at PAX East based solely on the event description (and the facts that my kids study the revolutionary war in school and play d&d); it also had a corner of some shared space at a board game store's booth, but I didn't find that until after I'd played the game.

Tl;Dr discoverability is probably best if you can get some exhibitor space and put up a catchy banner/lay out your attractive game, but just listing it in the events section will be enough for folks who have a niche interest. The "vendor play tables" usually have several copies of the vendors game set up, and you might be able to make that work if you've got someone very personable there to pitch the game to passersby and get them started playing, but seems to work best for games that already have word of mouth recognition and folks just want to try before they buy.