I'd put Advance Gunstar over Gunners Heaven, though not by a great margin. Gunners is very good, perhaps remarkably so, given how easily it might've been phoned in for the launch window. Has an unmistakable fiery passion that would've done the 16bit years proud.
In direct comparison with Treasure's game, I just miss the rollicking physicality Advance inherited. MD Gunstar has perhaps the most literal melees of any run/gun.

Wild plunges into massed hostiles, laying about the foe with abandon! A career-ending slide tackle to the poor fucks in front, pawns sacrificed in the vain hope of dinting your hellacious assault! Then dropkicking, frog-splashing, and frisbee-tossing their comrades' broken bodies left and right! Perhaps blocking a would-be HITMAN SHOT from the one sneaky prick, immediately revenged by a kick to his jaw so biblically FOTNesque, he is left flat on his ass gawping at the clouds in stunned revelation of
True Pain - and
True Faith! 
- before his stricken body detonates like a warehouse full of TNT!
Huge part of GSH's appeal for me. Advance captured enough of that crowd-crushing forward momentum to make me happy. I especially liked the new SRK.
Alien Soldier kept a bit of it with Counter Force aka
Cyber Birdman Bitchslap. Blocked by a Robbie The Robot whose cold steel armour refuses to burn, nor buckle beneath punishing artillery?
Just slap the daft twat Or body-tackle him with such spacetime-annihilating force, he sees the face of God in the flames of his own sub-atomic obliteration, and uses his last ever CPU cycle to repent for being an asshole!
Christ that's something else AGH recaptured, an opening stage I could replay ten times in a row without the slightest hint of fatigue.
^ old lame run - lacks sufficient slapping, disgraceful! Trust me, just tap [B,B] as you tumble out of that first Phoenix Force, you'll delete Robby's face with one good discipline!
Been ungodly forever since I last played Gunners, I should revisit. I just really like seeing it mentioned. It felt like a semi
"Did I just imagine that? Was it cancelled?" cryptid, before I got die interwebs and was reacquainted. I distinctly recall being so happy to see a loud and proud run/gun amidst all the artsy stuff I didn't care about, in the magazine previews. (I might care about them now though tbh! it's been long enough, let old bones lie ffs

)
Panzer Bandit, otoh, most definitely is an unofficial GH (the Saturn GH

) sequel. I think I lucked into the EZMODO pick, the cigar-chomping cyber commando dude, because I just liked his style. Smoulderingly glaring off the select screen with his steely red eye! Grrrr!
(■`w´■) Too cool to die super-buff metal commando dude! (`w´メ)
But I liked his grenade-chucking Rolento rolling even more, and apparently it breaks stuff, because I was keeping burning bodies aloft on a river of pain from the get go. Great game! I think I took to it more readily than Guardian Heroes itself tbh. The lack of chatter definitely helped.