Cultivators used to be mid-mount, but took a 1/2 day to mount & it was difficult to handle an 8 row or bigger size. With that much weight on the front wheels they like to get stuck real easy too.
I run a 15 row rear mount ocationally. You can really wipe out some crop if you don't pay attention! /forums/images/graemlins/smile.gif
I suspect one of the problems is, by the time you learn how to do it, you are done with a small plot. It just takes practice. You really only rarely look back to see nothing is plugged. I find going faster actually helps, keeps my attention up & the travel smoother & less jerky. I have hills, so have to learn to compensate for that.
Overall, the less you look back, the better you are.
Learn a center or axle mark that lines up, or build a rod or chain that you can see that bolts over a row. Follow that. Don't look back.
There are mirrors (Culti-Vision was one) that you can mount on the front & watch a row going through the cultivator.
There are even automatic guidence systems that mount like a quick hitch & shift the cultivator, keeping it on track. (Popular in sugar beet areas in the past.)
So, can be high tech.
The 'big' NH tractors that face either direction are only 110 hp, not really that big.
--->Paul