Rallys - More like motorcyclist gatherings... [So some rally riders told me...]
I've been to Sturgis 3.5 times [one was an early one.] -2013, 2014[e], 2015, 2019.
I went to Daytona in 2019.
I prefer Sturgis. I live in Western Canada. 13, 14, 15 rode from N. Alberta to Sturgis. 2019 was on a "sabbatical" and took in both that year.
Daytona had some cool aspects to it, but it was definitely "Trailer Week." It is different for sure, and the beach vibe is cool. The downtown strip has lots to see, as many are breaking away from winter.
Sturgis, being the middle of summer, you're in the thick of ridin' season. Great roads, usually great bands, lots of fun. I think a lot of non-riders are going now to get the music festival vibe. More twisty roads, and elevation
I've not done the other big rallys, but we did do the 113th Anniversary in Milwaukee for 2013. Great bands also, and lots of Harley-Davidson experience.
If you can, ride. I get not having time, nor the stamina to trailer, but leave a few "I rode mine" patches for those that did - ha ha.