I was going to message Odd this, but I thought I'd share it with everyone and get your opinions. As I stated earlier, with Training Roulette in effect, there is the risk of not having someone on hand with great healing abilities. To remedy this, I propose the following build for my MEC.
MEC Trooper Abilities
Squaddie; Collateral Damage
Corporal; Advanced Fire Control; with a great aim stat, you definitely don't want to penalize it
Sergeant; Vital-Point Targeting; the added damage could mean life or death, 6-8 damage with the default mini-gun is huge early game
Lieutenant; Jet-boot Module; an easy choice, Alloy SHIVs can provide half-cover in a pinch, anyway
Captain; Expanded Storage; +6 Health per battle is great, but not compared to the AoE healing abilities when combined with Restorative Mist, and extra mines/grenades. Plus +50% base ammo is very useful, especially when using Collateral Damage, which uses up two normal shots.
Major; Overdrive
Colonel; Reactive Targeting Sensors; once again with high aim, this is another good choice
MEC Upgrades
MEC-1 Warden; Kinetic Strike Module; This is superior to the flamethrower in many ways, it gives +3 movement, does 18 damage when fully upgraded and has infinite uses. With Advanced Servomotors, another +3 movement is gained, for a total of +6. The flamethrower is useful, especially early game as it can instantly kill Thin Men groups even on Impossible and against charging chrysalids, but the same damage could be done by using a rocket. (this assumes the heavy is already in position of course)
MEC-2 Sentinel; Restorative Mist; the purpose of this build, it restores +4 health to the MEC and all units with 2 tiles, can be upgraded to +6 and gains an additional use due to Expanded Storage. With Distortion Field from the Support Class, all nearby units in cover within 4 tiles gain +10 defense, so this is also a bonus. (note this ability can't stabilize critically wounded soldiers so a spare med-kit should be carried by someone else in the squad in case this happens) Also MECs and SHIVs can be repaired by Arc Throwers for +6 health once the SHIV Repair project is done.
MEC-3 Paladin; Electro Pulse; does 5 damage to all units (including friendlies) within 4 tiles, and shuts down robotic enemies for a turn.
While the Proximity Mines are very good, they're best used with a MEC with the Grenade/Mine combo to provide the best damage.
This is a
suggested build. It is only an idea on how to create a dedicated medic/support MEC, instead of relying on Training Roulette, because getting Field Medic, Revive, Savior, and Deep Pockets all on one soldier is nigh improbable. This also assumes that I survive long enough to make Colonel, though I have faith in our Commander's tactical prowess
Also, it takes 210 Meld to get a soldier augmented and fully upgraded to a MEC-3, just something to keep in mind when considering MECs or gene mods