Tanks vs Troops

Which is better, Heavy Weapon Platforms or Human Weapon Platforms? Submersible Weapon Platforms or Submersible Warm-blooded Personnel? The debate rages!

Pros and cons, in no particular order for now, include:

Pro:

• HWP/SWPs (hereafter referred to as "Tanks" are more expendable, and so can be used as forward scouts.
  • I'm not sure how we argue they are "more expendable" since even basic tanks cost as much as 10 raw recruits. By the time your men are skilled enough to be worth ten times that, are tanks still useful?
• Tanks have higher TUs and Firing accuracy at the start of the game, and probably into the middle.
• Tanks are cheaper over the long run, if they survive long enough, since they don't cost salaries every month. (Though I doubt the lifetime of an average tank is that long).
• Tanks are useful on base defence because you get free ammo for them.
  • But only if you hadn't bought the ammo anyway, which you would have done if you were using the tanks for anything except base garrison. And they still use up 4 soldier slots, so unless they are good combat units, they are 'useful' only in saving a small amount of money - peanuts compared to losing a base.
• Tanks seem to attract priority fire from aliens, making them highly useful as decoys to draw enemy fire, expose enemies, and thusprotect friendlies. Until such time as the tank gets killed, anyway.
• Tanks don't go to sickbay. If you can get them back to base with even 1 point of mechanical "Health" remaining, they get repaired instantly.
• Since each tank replaces 4 Soldiers, that's arguably an extra 4 Scientists you could hire instead of those Soldiers/Aquanauts. This might make a big difference early in the game.
• If you lose a tank, you don't have to train a new tank up. You just buy or build one and it has exactly the same stats as its predecessor. So, compared to relying on human warriors, this decreases your exposure to casualties, and decreases the necessity to avoid casualties.
• Unlike soldiers, you can keep spares laying around, and all it costs you is Stores space, not any salary.
• And if you have excellent manufacturing capabilities, you may be able to replace an advanced tank much faster than you can replace a soldier.
• Tanks are immune to stun, smoke and largely immune to incendiaries. This can be helpful if you use a lot of these types of materiele, especially early in the game when your warm-blooded soldiers are lightly armoured and susceptible to them.
• Each tank on the battlefield means 3 less units to move around each turn. And you don't have to mess about in the Equip screen before each battle, fixing their equipment loadout. A great labour-saving invention!

Con:

• Each tank replaces 4 soldiers in any battle. Is one tank really more useful than 4 soldiers? It almost certainly will have less overall firepower and less tactical flexibility.
• Tank weapons are generally less powerful / efficient, and more expensive to buy and use, than the equivalent man-carried weapon.
• There is no way to carry reloads for tank weapons, unlike man-carried weapons.
• Armour for starting tanks is rubbish, unless you use a mod such as the XComUtil "Improved Tanks" mod. If you are playing the game as designed, or as implemented, starting tanks are barely more than decoys.
• Replacing a basic tank generally takes longer than hiring a replacement new recruit (96hrs vs 72hrs)
• Tanks take extra damage from HE area effect attacks, being 4-square units.
• Advanced tanks can be very expensive to build and operate, especially when the hidden costs of materials and labour are fully accounted for.
• Some of the tanks are buggy, e.g. the Gauss SWP, the ammo costs for the Fusion tank, etc.

Any more thoughts? Personally, I never use tanks except perhaps to fill in after I've taken bad casualties. For that, and emergency base defence, I might keep one or two around. Other people swear by them and send one or even two on every mission, e.g. the guy who completed the game in record time. (That probably just speaks to having fewer units to move each turn!). Some think a tank is appropriate for a terror mission, when extra firepower is needed. Rocket launcher tanks (and their big brothers, Fusion hovertanks) are undoubtably impressive at clearing a battlefield, if you don't mind having nothing but roasted fragments left over to sell at the Geneva bake-sale.