After many years of trying other methods (other than casting flyline, at which I'm pretty mediocre)-- including spending heaps of money on IMX-type rods -- I'm convinced that the best way to hook and land steelhead in swift (4-5 mph) water is to spool up a fly rod with mono, pinch on split shot 18"-36" above the fly and 'chuck and duck'. You can either cast 45 degrees upstream and glide it or across and swing w/ morre weight to hold it down. It's an inelegant cast but the sensitivity with the line under the index finger is unmatched -- no need for strike indicators here -- plus the cast can be metered out to the exact inch, which helps if you're throwing to fish tight against cover. Of course, you still get the great pleasure of fighting the fish on a fly rod with a single action reel, too. (But the fly snobs will still look down on you.)
You could commit an even greater heresy by chuck n' ducking a jig and float, too, using fly gear. Last November I started a day out with a guide on the Feather River with a floating line, strike indicator, split shot and egg pattern. After a half hour I thought that this was a poor imitation of chuck n' duck. I figured I'd rather try my new float rod and if that didn't work, spool mono over the flyline and go to C & D. After I switched to the 10 1/2' float road, re-spooled my baitcaster with 6lb line and used the same terminal gear but fished it like a jig I had 12 hook-ups on the day. Never did get to C & D that day, but I could have done the same or better with a fly rod mono, I'm sure.