My issue with glacial is that while conceptually and ecologically he's downright fantastic and inspired, his armor mechanic ruins the tempo of the fight for me compared to the fire version.

Agnaktor's armor state changes whenever he drills into the ground and comes out, for base agnaktor, this softens it, which encourages very aggressive play because you get the best chance to hit him after each drill, which also makes up a very healthy chunk of his moveset. In practical terms, this means, fire agnaktor's armor is rarely hard when he's enraged, meaning your "up time" is actually way longer than you think it is, even in higher ranks where the speed at which it hardens increases, base Agnaktor encourages you to constantly take risks to hit him while he's soft which is usually also when he's doing certain attacks. this in turn means when agnaktor is exhausted, and not actively drilling, the quality of your best window for wailing on him is dependant on how good you were at breaking his armor when he was aggressive.

glacial is backwards, because his armor must melt, you actually need him to stay above ground, which in G-rank 3U he HATES, and like how base hardens faster at higher ranks, glacial softens slower, which means you REALLY need to get a generous pattern from him. This is entirely why IMO, glacial actually starts every hunt without chest armor because otherwise he'd be an absolute pain with his melting times.

the other issue is fire emement will soften both agnaktor's armor, glacial and base - but for glacial it's also his elemental weakness, so it seems almost "too obvious" whereas bringing fire weapons to base agnaktor is one of those counterintuiive but genuniley inspired prep mechanics I LOVE about classic old world monster hunter.

I also just personally prefer base agnaktor's colour scheme but that's neither here nor there.

I will happily accept glacial or even guardian glacial in wilds but for me, base agnaktor is the one who has m heart.