I've got Dawn's with the aluminum press plates on my planter.  I probably wouldn't have to have the press plates anymore, but I think they do help firm the soil better.  I have been very happy with the way the Dawn wheels work in tougher notill conditions and the fact that they help keep the seed slot from crusting over.  If I upgrade planters, I'm either going to move them or buy new ones, which is the best recommendation I can offer.  I haven't used the Schlagel's, so I can't comment on them.

Good Luck,

Mike