Overall, the eyepiece build is quite excellent, with beautiful fit and finish. Visually, the AFOV, when compared to other 82 degree eyepieces like the Meade 5000 Series UWAs, shows just very slightly larger. Exit pupil behavior in the field is also quite controlled with eye placement being very easy and little or no issues with kidney beans or blackouts.
Over the past few weeks I've observed a variety of objects, primarily using the Takahashi TSA-102 APO. After using this eyepiece for a number of weeks, one thing is for certain, it gives up little to nothing due to its age...and in fact does some things better. Like its 14mm sibling, the 8.8mm provides a highly engaging feel when viewing, more so than with other 82 degree eyepieces. Eye relief is not what I would call generous, but it is not tight either, and it is very easy to see the entire FOV. Another nice thing is that when moving your eye to observe near the field stop, the FOV stays completely visible with no partial blackouts. This makes the viewing experience all the more natural feeling.
As far as a list of objects observed, I did not catalog them all but a partial list includes: Perseus Double Cluster, Pleiades, Orion Nebula, Albiero, Rigel, M36, M37, M38, Jupiter, and others. The FOV of the 8.8mm was nicely uniform and dark, showing no lightening towards the field stop as some eyepieces show. In the TSA-102 the FOV was also sharp to the edge, except for the smallest amount of astigmatism right at the field stop. However, it took very purposeful examination to tease out the astigmatism there, so not something that was really evident. In testing for flare, none was evident when placing a very bright object just outside the field stop and letting it transition through the FOV. For very bright stars, like Rigel which is near magnitude 0, some very minor and ghostly eyeball glint would surface now and then, but again it was nothing overt or obvious and I would have never noticed it if not testing for this specifically. The newer Meade 5000 UWAs, with their more modern coatings, did not show this behavior. This did not show on any stars less bright than Rigel. Overall, this vintage 8.8mm did extremely well controlling unwanted light artifacts. Across all targets, color saturation was displayed very well with carbon stars appearing richly orange and red, faintest stars in the FOV were just as visible compared to the views with more modern eyepieces, and nebula appear bright and detailed, with the mottled structure of M42 being nicely portrayed. Finally, scatter seemed just a little more controlled in this older Series 4000 than what I was seeing in the newer Series 5000 eyepieces. Star points and focus snap similarly had a quality that appeared just a little more pleasing. In examining the diffraction patterns of stars I would say that that the diffraction rings appeared just slightly less bright in this Series 4000, which might be why star points seemed a little more pleasing.
From a practical standpoint, ignoring all the miniscule and picayune optical details that needed very critical observing to ferret out, this vintage eyepiece was simply a total joy to use. The engaging quality of its exit pupil ergonomics and the uniformly rich dark background of its FOV made this eyepiece as pleasing of an experience as could be expected and also made it a worthy companion to the superlative Takahashi telescope I was using it with. Overall, I was suitably impressed with this eyepiece, as I was with the 14mm UWA I had borrowed long ago to test. So much so in fact, that when a full set of the vintage Meade 4000 UWAs recently became available on the used market, I snatched them up to become the staple 82 degree-ers in my own eyepiece stall!