I have had some trouble dealing with vehicles in my usual Ork lists, which include lots of boyz, some trukks, some HQ units and Nobz with Klaws, and Kanz. I want to up the anti-tank output of my lists and have been evaluating Ork anti-vehicle options.
Here are a couple that fit under 200 points:
6 Big Gunz (Kannons)
3 Mek Gunz (Kustom Mega-Kannons)
So the lootas put out a lot of with medium strength, a small AP, and weak damage. but it's a LOT of shots on average, and it's a lot of range. The TankBustas have better strength, damage, and AP, all of which is relevant. But firing only one shot each and short ranged. the reduced rate of fire is a problem also. I feel like these would be in positions that would make them easier to kill. On the other hand, I could put them in a Trukk and since it's assault, I can drive around while shooting. That's a lot of points though.
The Kannons seem like a pretty solid choice for the price. They deal 7/9ths of a wound per Kannon against a Razorback/Rhino profile, which with 6 of them will deal... almost 5 wounds per turn. Which isnt' amazing, but it's something.
They are stationary and vulnerable, but the range is ok.
The KMK Gunz seem like they have a lot of potential. 3 of them could put out about 10 shots per turn on par with the TankBustas with more range, though again this is a heavy weapon, and with better accuracy while stationary thanks to being manned by grots.
Thinking about defensive profiles, none of these are great. It seems like Lootas might be the simplest due to having the longest range and therefore the easiest to keep alive. I actually have the models for 3 Kannons so I may run those at least for now. What has worked well for you?