Re: Umpqua UPG Daytripper
I have a Day Tripper box. It is a good fly box and considering how many flies you carry, a guy could definitely get away with it as a primary/only box.
The features that are nice make it a lot different from the standard boxes mentioned are the two magnetic areas on one side - they are perfect for dropping your midges and they stay put and you can easily pick one, unlike trying to insert a size 20 or 22 hook into a slit foam slot and worse, trying to get just one out of one of those slots. On that same side of the box, that big middle flat is perfect for soft hackles, wets, nymphs, and/streamers. (I had probably 50 flies in that area alone before a remodel job I did other night out of boredom.) Then there are two rows for standard dries or whatever you want.
The opposite side is just rows of slit foam, but with a couple larger areas to hold dries up to #10 if you had them.
It is pretty easy to organize this box side to side, i.e. wets/nymphs on one side, dries on the other, or whatever you like. Also the box is thinner than all other double sided boxes. I carry one Day Tripper and one C&F large box with compartments on one side and slit on the oppo. The Day Tripper holds more flies, is lighter and thinner than C&F.