Pure tech structure is OST or SU building.
I hardly call Panzer Schwerer only a tech structure, I mean, what tech structure is able to kill T34/76 in 1v1??
It keeps infantry and light armor at distance. It kills them very well. It is your first "unit" to protect your frontline. Hardly any tech structure can do that.
As for the people saying that OKW is designed from the beggining to put trucks out of the base - sure, but if you use that argument, I must remind you that OKW was designed to put 1 Truck on 1 point to creat chain resource, not all 3 trucks next to each other.
See my reply below. It should be very powerful since it has no heavies (although that's argument for buffing lots of Ost/SU commanders who have no heavies or good off map) but being able to one shot such a large fuel investment in a fuel poor faction is dumb. I mean the V1 in vCOH didn't even do that to full health British trucks. Now if they made it do half trick damage then I'd be fine with that. But definitely not annihilating full health truck