One thing about aberrations - their presence/appearance does not necessarily indicate that there is something wrong with a given eyepiece. Instead their presence is an indicator of many different conditions predicated by the scope-eyepiece-eyeball combination at play.
Some aberrations are unavoidable, such as coma in Newts, and eyepieces will be able to deal better or worse with it. How severe the coma is is also a function of the focal ratio of the primary mirror, and coma correctors are optimized for specific focal ratios, say centred around f/4 or f/5, with a half f/stop either side. So an f/5 corrector in an f/4 Newt won't clean up all the coma present. Like wise an f/4 corrector will over correct in an f/5 Newt.
Other aberrations will be noticeable as a result of an excessively fast focal ratio that is beyond the design parameters of the EP.
Aberrations do not indicate a poor eyepiece either. What it can do is offer really good value for money if what aberrations are visible are totally acceptable to YOU. A wee amount of astigmatism along the very edge of the FOV of an 80° EP is no real problem as you do not ever do any observing along the very edge of such an EP. You don't. You move the scope. So such a $250 EP may be an absolute bargain for you
And if you rather drop $1000 on an EP, great too
Alex.