A little bit, yes. I miss on the toe occasionally ... Maybe 2 or 3 times a round ... And with my i20s, there is very little lost on those shots. With blades I'd lose quite a bit of distance on those shots. Now, I could still miss the green and not get up and down with my clubs, so I'm gonna guess at worst, blades would, at this point in time, cost me a shot, maybe 2, a round.
Of course, it's also possible that after playing with blades I would be more conscious of avoiding those toe hits since I know it would hurt me ... So maybe only 1/2 a shot a round or so.
I do like blades (i love the look of mb712s, and liked the callaways when i hit them too) so someday I probably will get a set just for shits and giggles. :)
I should elaborate on this one a little bit. [I got a little sidetracked on the whole semantics debate about what is and what isn't technically a blade ... not very useful to OP]
Yes, blades would cost me 1/2 to 1 shot per round vs. my current i20s. However, that doesn't mean that they would cost me those shots vs. any type of cavity backed iron. Not trying to be a Ping shill here, but the amount of forgiveness I get from the i20s on those toe hits is absurd. I kid you not, I can hit shots that actually leave a mark that is partially OFF the end of the grooves and have it still be a good shot. I mean, that is like 3/4 inch, maybe a full inch, off the sweet spot, and it feels almost the same as a solid hit and it travels almost the same as a solid hit. (Not everytime, but it does happen)
My old cavity backs, on the other hand, (Titleist DCI 981s, a cast version of the current CBs) played more like blades than they do my i20s. Anything out on the toe would go half as far as it was supposed to, and to add injury to insult, would rattle and hurt my hands.
The conclusion I'm slowly getting to is that if your miss is out on the toe and you play SGI irons, or maybe some GI irons as well, then yeah, you're probably going to cost yourself some strokes by switching to blades. But if you are already playing small players cavities, like Titleist CBs or MP-59 type clubs, I doubt that you will notice that big of a difference.
Further, if your miss is NOT a toe miss, then you probably won't notice any difference (as far as playability ... obviously distance and trajectory will be a little different). I strongly believe that is the only big difference between forgiving and un-forgiving clubs ... the performance on toe hits. That's it. If you're a 30 handicap who does not miss on the toe, you probably are not going to lose much playing blades vs. something like x-hots. This is why I don't generally agree with the idea that you have to be good to play blades. You just have to have the right miss.