I have used XP for planting for several years.  Repeatability has been very good for me but not guaranteed.

On several occasions, I have planted corn and later came back to plant soybeans right beside the corn.  I generally pull in on the planter tracks from the corn (it's usually not up yet) and shift the line if necessary.  Usually it has not been necessary. I have the ability to drop my markers if I desire but this doesn't help in this conventional tillage situation as the planter mark would be disturbed by the tillage pass for the soybeans.

I often use the AB line from a prior year.  I pull in on the edge of the field and try it without dropping the planter.  If this does not seem proper I could shift the line but the majority of the time it is fine.

RTK would do a better job of this but XP suits my purposes quite well.