I’m pretty much a amateur/beginner boulder, so take the following with a grain of salt (going by memory here on the first two).

Rockface: Haven’t actually been bouldering there, but is basically a “cave” with one vert wall and one overhanging (30deg or so from memory) and a few pull up balls (the one from ceiling) and other training devices. Not huge and not a lot of light in the cave. Haven’t actually climbed here.

Hangout: I like the gym, but the bouldering is a bit limited IMO due to height. Cool little cave to play around with but not much past head height. The main wall is overhanging, maybe 30, maybe a little more? Not sure what the problems are like, I’ve just mucked around on it prior to toproping. Several training things at the back. They have a millenium falcom volume though 😀

City Summit: Went recently. Pretty good area of walls (looks smaller than it is as its ‘folded’). Really high (think 4-5m) but really good landing pads. Some really interesting problems requiring good problem solving and careful moves/sequences. The long routes gives good long climbs (for bouldering). No long steep overhang sections but the overhang section has some fun/challenging routes (didnt try the mid-harder ones but looked interesting). Go up to V-silly grade. Quite a few training tools too.

Boulder Hub: New gym just for bouldering. Not quite as high as City Summit, but still pretty high, so you can get nice long runs. Some really easy routes on the overhanging (great for starting as some only place hard problems on overhangs so hard to start out). Some cool routes, but from memory (only the first 2-3 grades) a bit more straight forward than city summit. Need to figure moves, but less puzzly/contorting at least from what I climbed. Not sure re higher grades. The holds are nice, but super rough texture so watch your skin, or tape. Several training things from what I remember.

Hopefully this helps. Maybe some more advanced boulderers can give their thoughts re harder grades/more experience with diff layouts.