I like the general idea, although not the specifics.
If you want it to be an information warfare tool, then it shouldn't take up 3 module slots, as this would make your scout mech a one trick pony. Since they lack other abilities, scouts need to have different scouting abilities, such as the ability to launch UAVs, air strikes, or get target locks from outside standard range.
Instead of taking up a large number of module slots, you could make it take up a number of critical slots, because heavy and assault mechs tend to use up all their slots on big weapons and double heatsinks, while light mechs often have a lot of free slots, even after upgrading to Endo and FF armor. This would enforce the light mech's role as a scout, while removing the current problem of every assault mech being a one-man army, and impossible for light mechs to sneak up on.
Needless to say, if the module weighs 7 tons, it's only going to be used by heavy and assault mechs, and never used by light mechs.
Really though, I hate to see the seismic module having such an important role in the game. The focus in canon is always the radar, with active and passive mode, and the inclusion of Angel and Guardian ECM. The high tech (i.e. magic) of a seismic module being able to pinpoint the location of up to 12 enemy targets by having a split-second contact with the ground as the legs propell your 40 ton mech over 150 kph is just so ridiculous that we might as well just add a "fireball module" and "chain lightning module" and call the game World of Mechcraft Online.
Edited by Alistair Winter, 25 July 2013 - 10:03 PM.