If you've used dowels in the past I see no reason to decide to make this overly complicated with tenons although you certainly can.
The thing with dowels is if you have a decent dowel jig it becomes zip zap zowey quick, easy and sturdy. Like Tim I'm not a big fan of breadboards either, but to each their own.
Tenons are far easier to screw up while dowels are a piece of cake. My last project was with 2" 1/2" dowel an inch on both ends. It ain't falling apart any time soon. 48 overall dowels and they all lined up right the first time..
I figured it's time to change my signature so hold your breath. This is it.
Marty or Marty Farty if you feel mean.