I don't have a Krogan Vanguard so I can't rightly say anything about it aside from what I've seen unfortunately :(
If you wanna talk about glass cannons, then look at the Geth. Freaking 400 hp and 1000 shields. They get Hunter Mode which pretty much boosts damage, speed, firing rate, and let's you see through walls, but it halves your shields. Yay!

Infiltrator cloak damage buff + Infiltrator Sniper Rifle damage buff + Headshot damage buff + Widow or Harpoon Gun + Hunter mode = godlike damage. Be damn sure you're completely safe from enemies before attacking. Probably my second favorite class.

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I hear your melee attacks as a Geth burns shield too but yeah my girlfriend was really holding out for that one and I can see why, seeing through walls + sniper is like Red Faction 2's rail gun, especially with the widow which goes through light armour.

Personally a class I feel gets a hard deal is the Batarian sentinel. They have blade armour which puts more emphasis on melee damage I think compared to regular sentinels yet their heavy melee is one of the slowest (if awesomest) in the game. You'll take a good bit of damage before it lands.

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The heavy melee attack for Geth has them hug the ground and produce an energy field that damages those who get close to it. It disintegrates anything that gets killed by the attack. I find it somewhat useful.

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I dunno...is the AI so dumb that they'll approach a stationary forcefield of doom? I have a lot of credit for the Mass Effect AI, especially Cerberus engineer's turret placements. Though Geth in ME3 confuse me.

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The Geth's heavy attack is meant as a "get the hell off me!" type of move. Sorry if I made it sound like the AI is really dumb, but I've had quite a few enemies derp into my forcefield of death.

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Well nevermind then, can't account for everything I guess though I just don't get the geth. Based on the fact you still fight the Geth in Multiplayer it must be set before any potential 'destruction' or 'sentience' that can occur in the main plot. So why oh why are there loads of Geth who are operating independently of the Geth Agenda to side with the Reapers? Legion is a mystery enough, it's no longer dealing with 'heretics' the Geth are consciously siding with them yet it's acting against the Agenda. Now in multiplayer there are other Geth who have....semi-sentience to fight against them.

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