Have you ridden the Secret Service any appreciable distance? I own a Workcycles Fr8. I know it's heavier than the Secret Service, so this may not apply completely, but I could not live with it as my only bike. The build quality is phenomenal and the ride is incredibly stable, but it is slooooow. I own it because I regularly haul two kids and lots of cargo and for that reason it is my primary bike. But when I need (get?) to ride solo and don't have a lot of cargo or need to go more than 10 miles, I hop on my Windsor Kensington 8 from Bikes Direct. I feel like I'm flying when I get going on that after several days of riding the Fr8. I'm actually in the process of trying to figure out how to add an e-assist to the Fr8 and it's proving very difficult because of the roller brakes and the placement of the front rack (which limits caliper brake alternatives). I know you say you've narrowed it down to the Secret Service and the Betty Foy, but have you considered the Yuba Boda Boda? It has a step-through frame, is very lightweight, fits on standard bus and car racks by spinning the front wheel, and has the option to add the frame-mounted "bread basket" rack (though I think you'd have to modify it a little for your dog, maybe add a basket in the basket).