I wasn't real clear in my original post. The Miata is for camping trips with that rig pictured. The Fiesta would only be seeing tire/tool trailer duty ... same trailer but much less "accessorizing" resulting in a smaller and lighter load. I am likely to travel several hours to autocross events and like to carry more tools and spares than I want to cram into the car itself. I like the flexibility of having a hitch on just about any car for anything from a bike rack to an appropriately sized trailer.
I have had my share of "proper tow vehicles" in my time (F250 V10, Honda Ridgeline). With gas costing what it does these days, my '12 Focus plus a 5'x8' utility trailer makes an excellent light haul solution that averaged 32mpg over my recent 3200 mile round trip to Florida to move my mother back home. Very stable, safe, and efficient. Best of both worlds if you ask me.