There is no comparison or replacement to fishing NE Iowa's Driftless Region coldwater streams for trout. But I do enjoy flyfishing these lakes for trout as well, and this situation poses its own unique set of challenges.
Finding the fish is always the most important key to a successful outing. The saying "90% of the fish are in 10% of the water" seems to hold true. Once found, you gotta present them a fly they will try to eat.
The best fly seems to change over time. Trout have teeth and will shred a fly over time, so easy-to-tie patterns get my vote. Year after year Woolly Buggers in various colors have caught more of these freshly-stocked trout than anything else. #10-#8 Woolly Buggers seem the perfect size. Depending on the depth the fish are feeding in, I tie some unweighted, some with glass beadheads, and some with brass and tungsten beadheads. Best colors often include Gold, "Chili Pepper"(copper-colored), black, white, brown and olive. The gold and copper ones are flashier, and seem to get the most attention from the fish.
I flyfished one of the Urban Trout lakes 3 days so far this season, and caught 34, 39, and 64 trout, respectively. Weather conditions covered the spectrum from "good", to "super-windy", to "rain". You never know what you'll get, you just gotta keep fishing!