This has been discussed in a number of other threads, so you might do a bit of searching.
The bottom line is that all the apps have different vibes and different communities, and indeed the same app can vary widely based on the city. For example, in my area the app Jack'd has strong following in the Asian and African American communities, while Scruff is much more Caucasian and Latino, but not exclusive.
In my experience, most people have profiles on many apps because you never know where you'll find someone interesting. At various points I've had profiles on Grindr, Scruff, Jack'd, Surge, Hornet, Daddyhunt, Manhunt, Growlr, Adam4Adam, Hole, OKCupid, Match, and Tinder. Sometimes active on all or nearly all of them at once.
The comedian Joel Kim Booster has a bit where he refers to having multiple profiles on multiple apps and he calls them, "checking his traps." It's funny, but it's also on point. One app is not the end-all.
As for "hookup" versus "dating"... it's really up to you how you use the app. If you make it clear in your profile what you're looking for then you will find people will self-select based on what they're looking for. But it's also important to be realistic -- most relationships are hookups that somehow kept on going. I have dated people for many months who I met on a more hook-up oriented app. I've hooked up with people from Tinder. I had a 4 year relationship with a guy I met on an app where my profile was very hookup oriented. You never know what you're going to stumble upon or where.
If you want to use the apps to take 10 loads a day, you can do that. If you want to occasionally have a hookup, you can do that. And if you want coffee dates only, you can do that. It's just a matter of you stating your intentions and also making sure you're being realistic about what you want and need. You can have a profile that focuses on dating, but when you're horny... you're horny.
Try them all, keep profiles everywhere. Check them periodically and if they aren't doing anything for you, then close them and move on.