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!
 
