The Middle Deschutes is very good fishing and anywhere from Bend to Lake Billy Chinook is going to be good. The best fishing is early morning to about noon and then from after dinner to dark. 
One of the things I like about the Middle D is the simplified fly choices compared to the Metolius. When I used to live along the Middle D I kept a 7 1/2′ 4 weight strung up on my front porch and had a little chest pack with my grandfathers aluminum fly box filled with Renegades and X Caddis and Yellow Sparkle Duns and never lacked for a fish in the evenings after work when I fished several nights a week. 
Mornings are also great for a Euro Nymph or a Strike Indicator methods. Brown Jig Napoleon, Soft Hackle PT, 2 Bit Hookers, Hares Ears and Red Copper Johns. 
Besides the dry flies I mentioned above, the Purple Haze is one heck’uva a Dry Fly and I’d have to call it my #1 choice for the Middle D.