Bosch mechanical injection, even on a '73 Merc 450 SE, was exponentially superior to the shitty Solex Carbs with automatic choke as fitted to the non injection Cologne V6 
It would have been criminal for Ford not to fit it to the 2.8i 
Unfortunately, it doesn't work very well on on the 2.8! They're pretty poor for torque anyway, and the injected ones have terrible throttle lag; it's as if the throttle cable was made of knicker elastic. Anyone who has tried a 3.0l against a 2.8 will realise that Ford simply lied about the
160BHP, as the 3.0l(with a pretty optimistic 138BHP in a late Capri) will stomp all over a 2.8i. And the 3.0l is best used attached to a length of chain with a boat hanging off it. Neither are exactly durable or economical. Both engines suffer from the stupid nylon timing gear stripping, assuming that the oil pump/distributor drive doesn't twist apart first.
The 12v 2.9 is what either V6 should have been from the start, it makes a decent amount of torque, revs like a 2.8, returns decent economy on unleaded fuel(neither of the earlier engine last for long) and has a proper timing chain. Fitting one is the best thing you can do to anything afflicted with a 2.8. Doing that turned my 2.8i Capri into the car it should have been from the start.