Well, I did get to use them. They are absolutely superb. The comfort is excellent. With the soft rubber eye cup they felt a bit more comfortable then my XW10. You can sort of just rest for face on the eye cup. No difficulty in eye position what so ever, much like the XW10. Contrast, color tone, sharpness and light through put is near as makes no difference as good as the XW10. No perceivable coma in stars at the outer edge at F5 in any of them.
I think the raise-able eye guard in the Delos is better then the XW10. Considerably quicker to put into position. But, that's a moot point really when you only have to put the eye guard up once at the start of the session.
The XW10 however, clearly does a better job on light scatter on really bright objects like Jupiter and Sirius. The Delos were still just as sharp but the XW10's view had almost no light halo around the object. It was obvious on Jupiter at first. But, if you can focus your eye on your target it sort of disappears and you don't notice it there after. Another place where the XW shows its strength is its size. Definitely smaller then the Delos eyepieces anda bit lighter too.
But, the 8mm Delos and the 10XW beautifully split Sirius at 187x and 150x respectively. Sirius B is hiding in a diffraction spike for me so I was not able to see it at 107x with the 14mm Delos.
On Jupiter. I have to be honest. Ive never seen a better view then I did last night. The 8mm Delos and 10XW showed me things I had never seen before. I could see clearly 4 bands. The GRS was clearly visible in both the 8D and 10XW. The bands were not just brown lines either smeared across the front of a ball. I could see swirls, wisps and other shapes as well. It was truely marvelous.
Deep sky all these eyepieces were sharp as a tack. Easily seeing E and F star in the Trapezium in Orion with the 14mm Delos at 107x. The contrast and the sharpness brought out very impressive detail in the nebula even though I was observing right in the center of Sydney. The view was naturally only improved even further with the introduction of a UHC filter.
I was able to observer a small handful of open star clusters. They both perform fantastically. Completely flat fields and tack sharp stars from edge to edge. Its amazing how sharp,tight and pinpoint stars are in these eyepieces. I thought I was looking through my AR102 instead of a Dob with diffraction spikes.
I would have looked at more target but the clouds rolled in. All in all a good first light for my 2 new Delos. Definitely keepers indeed.
It means in the new year though I'll selling 4 of my ES eyepieces. Not my 30mm ES though. You'll have to pry that one from my cold dead hands.
I might use the funds raised to get a XW7. 214x is a nice mag boost from the 8mm, but still useable most nights. Don't think I'd get the 6mm Delos though. 250x is just too much to be regularly useable.
To answer the question of the difference between the 10mm Delos and the XW10. Don't think it really matters. You cannot possibly go wrong with either.