We have been using tramlines for over 10 years now.  I don't have any data to compare yield, but I will use tramlines just for the convenience.  We use tramlines in wheat and beans both.

Some general guide lines follow.

• The sprayer needs to be some multiple of the drill width.   An even number will work (like 30' drill and 60' sprayer) but odd number are better (30' drill and 90' sprayer).
• Erosion can be a problem in the tramlines, but usually is not.
• The ideal way in my opinion is to divert the seed from the closed row to the adjoining row, but again this not absolutely necessary.  We are just shutting of the rows on our current drill.
  
• Spray one time with tramlines and you will not want to spray with out them again.
• I don't really suggest trying to kill the tramlines post emerge.  It is much better to put them in with the drill.

I built my own tramline controller.  I found a solid state "counter module"  (I don't remember the brand) in an electronic house in town.  It has a built in relay.  I have an implement switch on the drill that trips every time the drill is lower.  I use a linear actuator to close the doors at the seed meter.

My current setup is a 30' Deere 1890 CCS followed by a 60' sprayer.  My tramlines are on 120".  I am using RTK so that when I plant corn the following year, the tramlines are between corn rows.  I can fold the wing on my sprayer and spray 45' on the first pass.  The puts the sprayer and the drill on the same tracks.  My next sprayer will be 90'.  That will negate the need for the partial width spray on the first pass.

Tramlines  work well in both no till and conventional tillage.  Once you make one pass on the tramlines they will support the equipment and you have very little problems rutting fields.  I don't think we have every been stuck running tramlines.

You have my number, call if you want to talk.