ahh the Thor. The Thor goes great with tanks, because its now mainly a anti air unit, if you can get the gas to produce both in decent numbers, and they have a high hp and fire power. Something I didn't like about the Thor being an anti air unit is it's very susceptible to micro from fast air units, since the Thor shoots off a volley of missiles for 1 attack it's a good idea to micro it to death. It's also slow, and a little too easy to avoid with Mutalisk etc while you abuse other areas of a base, it's also too big and is usually focused on and can go down quick if it doesn't have the right support.
I think they should scale it down, take off a lot of the armor, and call it a Goliath lol, but really it's a good units just need to be scaled a little. I like that it was more anti air and more tougher or a unit than the Goliath was, so it's a nice fit into the Terran mechs.

