The which is better debate has been beaten to death for just about every art that's out there. It really does depend on you, what you want from the art specifically and your instructor. Aikido can be very effective if that's what the school and instructor gear the training towards. Same with DRAJJ. If you have a school that is geared toward getting the kids into the dojo for after school programs then it's probably not gonna be very effective.
Now, as to which will be effective more quickly, all other things being equal, I'd have to say that the DRAJJ will be. Getting the more advanced ideas of Daito-ryu will take a long time, just as aikido, to grasp and implement. Remember that aikido traces its' lineage back to DRAJJ by most accounts and what you see in the aikido dojo you'll see a variation of in the DRAJJ dojo. Good luck and keep us posted.