Is a Kuhn drill right for all situations?
I have been looking at the Kuhn sd 4000 drill and heard good reports from a contractor using it to direct drill rape into unmoved stubble but would need it to drill into a variety of surfaces including pressed discing and some pressed (and probably rolled) ploughing will it be suitable for these different surfaces? (Farm is 1200 acres mainly Cotswold brash with some medium clay.)
I am sure this drill can be used as you describe.
The key for me is having a drill that is right for you most of the time. These disc drills are excellent for direct seeding into stubble but require careful management in a plough situation. It can be done but they are not at their best.
So work out which is the main situation you are going to be working in over the next five years and go the drill that will work best in those conditions.
For example, if you are going to direct drill over 50% of your farm, on average, then go for this type of drill. If you are chopping most of your straw you probably need a tine drill.