There's a rumor going around that blades are for low-handicappers only.
Middle- and high-handicappers should stick with cavity-back irons.
Game improvement irons.
Like most rumors, this one doesn't stand up to scrutiny.
Blades, or more correctly, muscleback irons, have a fairly flat back with extra weight on the bottom of the clubhead, which helps get the ball airborne.
The weight distribution of a muscleback, though, lets a mis-hit be a mis-hit.
A cavity-back iron, with weight distributed all around the perimeter, tends to smooth out mis-hits and keep the ball going straight.
This works against the intentions of players who like to work the ball.
They tend to be the better players, and they use blades.
Hence the rumor.
But there are other reasons why blades have a devoted following.
More weight is concentrated behind the ball because the clubhead is smaller.
This means that when the ball is struck it has more authority, and the sweet spot is thus much sweeter.
You also get more feedback with a blade, since you can feel exactly where on the clubface the ball was struck.
For a long time, every golfer played blades because that was the only type of club there was.
Unfortunately, unless you have good hand-eye coordination, it is hard to hit the sweet spot, or sufficiently near it, every time.
Off-center hits resulted in wasted shots.
Hence the introduction of game improvement irons.
Modern blades do have some forgiveness built in, so an off-center hit can still give you a useable shot.
In addition, hybrid irons are becoming fashionable, and for good reason.
They are lots easier to hit than long irons.
They now replace long irons for many golfers who now carry nothing longer than a 6- or 5-iron.
That makes it quite sensible to have your 6-PW be blades instead of cavity-back irons.
It is really not that hard to hit a short iron in the center, because the swing is not that big.
Blades at this end of the set are now a reasonable option.
The other benefits of blades listed above can be available to you.
No golfer should be reluctant to try out a set of blades and find out how it feels to hit them.
True, there is a bit of snob appeal -- they are the sports cars of golf.
But there are serious benefits to using them and you should not be dissuaded unless you have tried them for yourself.