Recessed versus non-recessed simply comes down to player preference.
The myth that you cannot pull up on a non-recessed Floyd is false. I have two Custom Shop Jackson’s with non-recessed Floyds as well as a US Jackson and US Guthrie Govan Charvel with recessed Floyds. They are all floating. Every guitar that I have owned since the mid 80s had a Floyd on it. All 4 of these guitars pull up. My non-recessed gets 2 half steps of pull up. My recessed gets 3 half steps of pull up. I can play Brad Gillis solos on my non-recessed, so the pull-up is anything but minimal.
It is true that some recessed Floyd routes allow for a bit more pull-up, but this is a function of the routing of the tremolo cavity (particularly the depth of the route that sits directly beneath the fine tuners and string retainer screws) not the method of mounting. A non-recessed Floyd in fact could be routed to afford more pullup too.
A factor that does affect pull-up is the size of the block. A guitar, whether recessed or non-recessed that has a standard sized route for the sustain block and contains a “big block” sustain block loses most to all of the ability to pull up. This is because big blocks are considerably thicker than standard sustain blocks and this additional thickness was added on the side of the block that moves toward the body when pulling up. This was done so that the added mass would not affect dives. It is possible to route the guitar so that you do not lose pull ups when using a big block (as Charvel did with my GG).
The myth that you cannot float a non-recessed is false. As is the myth that a non-recessed is blocked or sitting on the body. If you look at EVH’ Frankenstein you will note that the Floyd did not sit on the body, he screwed quarters into the body that extended beneath the tremolo base plate, thus blocking the tremolo.
The myth that action/string clearance is higher on a non-recessed is false. The action is merely a byproduct of how a guitar is set up. The same action/string clearance height can be achieved on both a properly built non-recessed and recessed guitar.
Now, there is a difference and this is where player preference comes in. With a recessed Floyd there is no neck angle/neck pocket shimming required to get the correct action/string height. This is how Fender guitars (e.g. Strat, Tele) are Built, so a recessed would give more of Fender Strat type of playing experience.
Non-recessed Floyds do require a neck angle/neck pocket shimming to get the correct action/string height. The angle happens to be the same angle that Gibson uses on their guitars (e.g. Les Paul), so a non-recessed guitar would give more of a Les Paul type of playing experience.