What are the differences between the M15 AT MINE and the M2 SLAM?

On Battlelog if states:

M15 AT MINE

High Explosive Anti-Tank mine that detonates when vehicles pass by in close proximity. Capable of a Mobility Kill on even the heaviest armored vehicles.

M2 SLAM

Selectable Lightweight Attack Munition usable as either an off-route Anti-Tank mine or a traditional land mine. Blast damage is less than the M15, but is still capable of a Mobility Critical on heavily armored vehicles.

I read both of these but don't understand the main difference. It tells that the M15 does more damage but then why use the M2 SLAM. Help anyone?

From wiki:

Unlike Anti-tank mines the M2 SLAM can be thrown, and at a great distance

and

They only detonate when an enemy player is in the vehicle they are strapped to

So it seems that it can "stick" to a vehicle. And that you can throw it fairly far(not sure how far). For me(I didn't play BF4 yet), it looks like a C4 that can be thrown like a grenade that detonates when it's driven over by a vehicle or if it's stuck to the enemy vehicle.

Wiki also says that it takes 3 of M2 SLAMs to destroy any tank or LAV

Place the M2 mines on walls, gate posts, static vehicles, etc. For the moment the M2 SLAM still catches drivers unaware, whilst players keep an eye out for mines on the ground ahead of their vehicle, they're not looking at the walls and parked vehicles along their path.

Where possible I've tried to get behind an enemy vehicle and place M15s behind them, then using an RPG to encourage the opponent to back up. It's easier to do with the M2 as you place the M2 directly onto the back of the enemy vehicle then shoot them (the mines) with the RPG.