>>1669644third option. Full size rack with basket on top to put your carry bag with valuables and flow over stuff like a box of food in. Can fit panniers and can strap drybags to. These are quite expensive.
>>1669644The difference really is the newer bikepacking style saddlebags don't need a support, or saddlebag loops. It would be strange to run one when you have a rear rack, and a brooks with the loops to attach a trad bag to. They're designed for systems without rear racks. You'd be introducing a load that can sway and is high when there's a platform to steady and lower it right there. They're also far more awkward to pack. I wouldn't want one to keep your go-bag with valuables in. Whereas a carradice bag is great for quickly popping a small shoulder bag in and out of. If you don't like the look of them or want to spend the money, you can just strap any old bag, like a drybag, on your racktop, for much the same affect as a meme modern saddlebag, but sturdier, better COG, and for way less money. But you do really want 1 easily accesable piece of storage to keep a small back with your valuables in, so if you don't get a carradice bag, i'd suggest you get a full size front rack with a basket on it to put that in. Those are the best 2 options for it imo.
also aero profile at the back is far less important as it's behind your body. This has been tested.