Well Universal and IOA are smaller than Disney so they can be somewhat more crowded IMO, BUT weekends at Universal are pretty packed. We try to go during the week. The reason is that they offer incredibly low prices for season passes and tons of Florida residents get them. Obviously they go on weekends more than during the week. Also consider this...We went last August and only had one day to spare. We insisted on going to both parks in ONE day, but we did it!!!! Lines were long, but they move fast and the best tip I have is to go in the "single riders" line. We were able to go on rides over and over with no lines and others were waiting over an hour. Most times we were able to ride together anyway. It was worth saving all that time. I really wish Disney had that system. So I guess the bottom line is that they can be equally as packed, but there is so much to do and with the "single rider" line, you can actually go on more rides in one day at Universal than you could at Disney.