I have several faster Dobs plus an NP-101. TeleVue NP series scopes are about wide, flat fields.
The NP-101 challenges eyepieces, it's fast and with the right eyepiece provides essentially perfect views. Eyepieces that are not essentially perfect in a fast scope will reveal their flaws.
The TeleVue MPT was designed to test TeleVue eyepieces and later the various Petzvals followed along that path, fast, wide and flat.
I use TeleVue Panoptics, Naglers and Ethos eyepieces and think TeleVue eyepieces are really the ones that best match the Petzvals. You really dont want to cut corners with the eyepieces because the scope will show the flaws. And the fact the TeleVue eyepieces are designed to be tested in these scopes means there's a certain synergy.
The bigger question is whether the NP-127 or the NP-101 is the ultimate scope for you. These scopes thrive on the deep sky and you need to be an low power wide field junky to appreciate them. If you're mostly a high power, planetary type, there are are other scopes to consider. You gotta love a big wide field that's as perfect as perfect can be because that's what separates these from the rest of the pack.
The same eyepieces that are well suited for an NP-127 or 101 are also good choices for a 12 inch F/5 Dob fitted with a Paracorr.
41 mm, 35, mm, 22mm Panoptics
31mm, 16mm, 13 mm, 11mm, 9mm, 7mm, 5mm and 3.5 mm Naglers type 5 and type 6s.
21mm, 13mm, 8 mm Ethos's
2 x TeleVue Barlow.
Not many have the 41mm and 35 mm Panoptics plus the 31 mm Nagler. But for one of these scopes, it makes sense because these are the views these scopes are about. If you think, just one's enough, probably an F/7 doublet or triplet will do the trick for you.
I'm sure the Delos are great, the Delites with their 60° AfoV tend to defeat the purpose of a scope like this though I am sure they perform admirably.
For these scopes, it's not just rounding up the usual suspects. For example, the Meade/ES 24 mm 68° eyepieces generally get high marks but in the NP-101, there are edge aberrations that are just not there in the 22mm Panoptic. If you're OK with that, then the NP-127 is not the scope for you because correcting that last bit is what these scopes are about.. From what I know about the Pentax XWs, I'd think they wouldn't be a good fit.
I've had my NP-101 for 10 years and it's seen a lot of eyepiece time. When I bought it, I really didnt understand what I was buying, I thought I was buying a faster app with very good optics and color correction and the legendary TeleVue build.
I did get that. But the whole refractor field curvature thing, I didn't understand. The flat-flat field, that's what I was buying.
I will add this. For me, I believe the NP-101 is a better choice than the NP-127. The NP-127 would be better at the higher power stuff but there are plenty of scopes for that. This is about the 4.9° field at 13x with the 41 mm Pan and the 4.5° field with the 31mm Nagler.