I think this whole subject is fascinating, because of all the variables involved. These include the type of plane, the blade, the chipbreaker, the sharpening method and the sort of wood being planed.
My experience has been as follows. From about 1970 I have used Record planes - Nos. 7, 5.5, 5 and 4. About three years ago I swapped the standard cap irons for Clifton two-piece cap irons (known as stay set cap irons when Record used to make them). These made a significant improvement to the performance of the planes but not as much as I wanted.
Then about two years ago I fitted Clifton blades which made a further significant improvement.
However, still not satisfied, I recently went the whole hog and bought a Clifton No. 7 and No. 4.5. Wow, what a difference
I think the marked improvement with the Clifton planes is a combination of things, including the weight (they are much heavier) and the overall rigidity which stems from the bedrock frog and the overall better engineering. And what a joy being able to alter the mouth without dismantling the plane
The difference is most apparent when dealing with very hard woods (at present I am battling with some very hard oak and not having a planer/thicknesser I am having to do it all by hand) or woods with knots in it. The planes have a smoothness in the way they operate and the blades seem to want sharpening less often - although I think I was sharpening more often before because the Record planes were not operating as smoothly rather than because the blades were blunting quicker. It's quite difficult to explain but it's worth trying a good plane just to experience how much better they are. I am sure the Lie Nielsen planes give similar results.
I want to experiment next with my sharpening technique. Currently I use DMT diamond stones (coarse, fine and extra fine) with WD40 - I hate any system which uses water because of rust problems and I found water with diamond stones far more messy than WD40. However, I might dig out the oil stones again because the extra fine diamond stone doesn't seem fine enough to give a really good edge.
Hope this helps the debate :?
Paul