Well... there is an interesting comparison - one which I hope Alex might read too. The first part is comparison of the TMB supermonocentric against other modern high-contrast eyepieces - by Gary Seronik and appeared originally in S&T.
OK, most of you will think it is OK to do this kind of comparison, and those of you using f/4 Dobs with a paracorr will be having warm fuzzy feelings.
But this is followed by a critique by Chris Lord (Brayebrook Observatory) as to what is wrong with the test - starting with why a fast Newtonian reflector is a lousy choice of telescope to do eyepiece comparisons:
http://www.brayebrookobservatory.org..._critique.html
But I think Chris Lord was also a little harsh - there are examples of eyepieces having been designed to match the aberrations of specific telescopes - starting with the (now rare) Pretoria eyepieces and RKE's. So in this respect if you have found an eyepiece that YOU like, on YOUR scope, I'd say fine, stick to it !
Now let's look at Alex's test. He used a larger fast Newtonian. Aside from whatever the eyepieces are doing, the diffraction-limited field of view in his scope is tiny - smaller than the FoV of the 13mm eyepieces for sure. Secondly the aperture of his scope means he wouldn't have come anywhere near the diffraction limit from his home. Then there is a question as to vignetting due to the secondary mirror - most fast Newtonians have secondaries that are somewhat undersize simply to avoid them exceeding 30% of the aperture of the primary - and lastly collimation - fast Newtonians are very sensitive to this.
Consequently any conclusions concerning off-axis performance of the eyepiece I would tend to take with a grain of salt because the effects of off-axis degradation due to the scope.
FWIW for a while I used an even more extreme 'scope - a 32 cm f/3.7 Newtonian - and knew all about what was wrong with fast Newts.
If you want tack sharp images at medium to high magnification nothing beats good-ol LONG LONG LONG FOCAL LENGTH, with a small secondary obstruction (none if it's a refractor) and virtually any eyepiece will perform well, apart from contrast.
Ultimately... this is why my current scopes are an f/7 refractor and f/15 Mak, and in some respects I dream of one of these
http://www.skylightelescopes.co.uk/. Maybe one day when I can afford a decent mount, and the country house to go with it.