Being a wee bit budgetarily challenged at the moment (stoopid engagement rings ) I'm undecided as to whether I should get a bottom cleaning bit or a dado cleaning bit.

There is one main task I have in mind for this bit which is to route out an area maybe 5mm deep of MDF for what I guess you could call a solid piece frame w/backing (or one piece framed blackboard).

Unless these bits can plunge, I'd make a starting hole with a straight bit to the right depth then use this new bit to clean out the entire area using a template jig. I don't think Forstner bits would work clearing the area because of the brad point, but please correct me if I'm wrong.

I don't use dado blades (currently) but I really like the bearing being there so instead of a starting hole, I could do a lap around the edge of the area to be removed with a straight bit then use the dado cleaner to take the inner area out. Or if it can plunge I'd do the whole lot with a template for the bearing to ride on and have much less fuss with changing bits.

Got any suggestions as to which bit could work better in this situation, or if there are other bits I should be considering?