Okay, finally managed to try out the new DLC units for myself.
GP03 seems fun, but it really needs a good partner to fully capitalize, it seems. Getting down the timing to do one bazooka shot instead of two isn't too bad (I say this now, but let's see how hard it is on Dun.net scenarios), but the demolition chain has the wonkiest hit detection and the beam cannon is powerful, pivots slightly, but has a ridiculously long start up. Other than that, GP03 has tons of missiles and bazookas that can juggle enemies before they can recover in mid air. If you're playing GP03 fairly close, you can follow up with a lot of melee this way. But if you have a good melee partner, GP03 can do some pretty sick set-ups. Its EX Burst is quite stylish, and GP03 does have a lot of ways to hit confirm into it. Too bad you can get cut pretty easily while using it.
Xi is kinda... odd. Its CSb missile spam is almost like the ZZ's CSa missile spam in the sense that it looks flashy, but its probably not going to hit anyone. But other than that, it seems like its Minvosky Craft mode blocks beams and adds some additional evasion maneuvers while lasting a decent amount of time. Beam rifle has a decent charge, but the key is that each BR shot also launches out two missiles (I don't know if there is an ammo limit for the missiles, because at times, no missiles would actually come out). So yeah, missile spam is Xi's thing. Hell, in some situations, the missile spam can actually cause the game to slow down.