Read my sig.
That said, I have played everything from a muscleback 2 iron (Wilson) to extreme cavity back (SE 600XC) to even the GolfSmith Special Force
irons (closed face).
Here's the deal, skimpy.
When you miss the sweet spot (which, contrary to popular hype, is the size of a pinhead - no bigger) you lose yards. This is why the amateur 'nukes' one every now and then. They simply found the sweet spot.
Now, musclebacks and blades penalize you more yards the further you get away from the sweet spot; compared to cavity backs. This has to do with weight placement. With cavity backs, the weight is more uniformly spread around the head, lending similar mass in multiple places to create 'forgiveness' - in other words, less penalty for missing the sweet spot. Blades and musclebacks, by comparison, have more mass located by the sweet spot, which leaves less material to 'spread around' creating more discrepancy between 1/4" off and 3/4" off.
So you need to decide for yourself whether you want more forgiveness or not. If you're happy with your current
clubs, swing away.