I set them up today but have to wait for a dry day to take them around town and to a park to give them the test I want to do, but once I've ridden them a bit I'll come back to write up my thoughts.
After a couple more months messing around with wheels I feel like I can come back to this post just on the off chance anyone needs yet another opinion on these wheels.
Long story short I ended up buying Spitfire f4 conical fulls to satisfy my desire for a faster hard wheel.
The x99s are a good wheel but did not feel different enough from a normal hard wheel to make it worth skating full time. They are just a bit stickier than I wanted, not at all like an actual soft wheel, just stickier than a hard wheel, while also being pretty rattley on rough ground.
I wanted a wheel that would be my perfect all-arounder, that I could skate from my house to the spot or park and do all the tricks I wanted there. I live in the northwest and the ground is pretty crusty and I live in an area with lots of bricks so it was a must that the skate around my neighborhood be tolerable, and I just wasn't satisfied. For that skating I don't think I can beat Dragons.
Skating at the park is definitely a bit better than with the Dragons, I'm sliding a bit further, tailslides feel a bit better. For dusty parks it definitely wins over your standard hard wheel, I'm not sliding out by accident on the x99s.
So I switched to formula 4 conical fulls as my standard park setup just to have something reliable and comfortable with good speed and slide, and I'll probably just keep switching back to the dragons if I have to make a trip across town or I know I'll skate some crust.
I was hoping they would be the perfect middle ground but they aren't quite there so I'll be sticking to the two sets of wheels for now.
The one place I prefer the x99s to either is actually indoors though. By hours the majority of my time on a board is indoors these days, I teach skating as my job and I'm mostly indoors for that, and the surfaces are always kinda dusty. For that specifically I can see myself keeping the x99s on my board for days at a time. Whether I actually do that just depends on if I want to go to the trouble to switch my wheels, because both the Dragons and the Spitfires would also do fine, I lose some slide with the dragons and some control with the spitfires, but both are tolerable indoors so its mostly a question of whether or not I want to go through the hassle of switching.