Riled up by the discussion in the comments section of this post, we caved in and bought a Minnehaha medium saddlebag from that place where it is on clearance [link removed since the item is no longer sold there].
The Co-Habitant attached it to his Raleigh DL-1 Roadster and it is a perfect match. Black canvas with tan leather straps - a simple, classic design. Those light strips are our own CatEye lights; they do not come with the bag.
We do not have pictures of the bag before the lights were attached, but above you can see it on our friend somervillain's beautiful Shogun (which I will be writing about soon). The Minnehaha looks as good on a stately 3-speed as it does on a regal randonneur.
The bag originally came with two reflective strips of fabric, attached to the leather straps via cords that resemble hair elastics (these are pictured above). The Co-Habitant removed these when he attached the lights, and now I will use them as actual reflective hair elastics when I cycle at night.
Side view of the Minnehaha on the Roadster. As you can see, the leather straps attach to the two saddle loops and to the seat post. If you prefer, the strap around the seat post could instead be secured to a rear rack, placing the bag at an upright angle.
The bag is voluminous. Dimensions are 11"W x 9"D x 9"H and it has a 10L capacity. A wooden support (visible inside, along the top) ensures that it will keep its shape. There is only one large compartment, which can be loosened or tightened via the cord shown in the picture.
The design is not complicated. It is basically a large, versatile bag that can be stuffed to the brim and will still look good. We have filled it with clothing, food, purchases, bottles of water, etc., and it has behaved very well. Attached in the manner shown, the bag is extremely stable and does not dangle. It also keeps its form even when empty.
One aspect of this bag worth noting, is that both the canvas and the leather come "unfinished", which some who purchase it may not realise. When treated with a water-repellent conditioner, the leather will turn a dark chestnut brown. So if you prefer that look over the black and tan, keep in mind that the bag will look that way once you treat it. We will probably do this eventually, but haven't had time yet.
As others have noted, the main drawback of the Minnehaha medium saddlebag is the location of its closure - which is so low that it's almost underneath the bag. One must either lean over or kneel in order to access it, and it's hard to see the buckles from either of those positions. The Co-Habitant also reports that he found it difficult to fasten the buckles at first, as the fit wasn't perfect - but over time everything stretched out and softened up and this difficulty subsided.
The final verdict on the Minnehaha medium saddlebag: We are very glad that we got it at the bargain price, and I highly doubt that anybody would regret that purchase. As for the retail price? Well, I still think it is a good value - simply because all bicycle bags are expensive nowadays, regardless of looks or quality, and even at full retail it is still less expensive than most. The Minnehaha bag is large, classic, and matches practically any bike. You can learn more about their full line-up here.