First, .8 lb. compared to the 2.3 lb. 20mm Nagler it replaced. Excellent contrast and sharp images right to the edge. If you like the 31mm, the same can be said about the Jr. 20mm. A winner.

My search for the best wide-field eyepiece is finally over ! Very expensive, but delivers excellent sharpness, constrast and detail across the entire field. This focal length is just about right for the 480mm Stellarvue - enough magnification to see individual stars in Auriga star clusters, and 3.4* field of view to find them easily. Eye relief is a bit short, and the eye vertical position is not very forgiving due to mild blackout if one is too close to the lens. Other than that, no complaints except for the price ! Trapezium easily resolved anywhere in the field of view !

Im not so sure about that 12mm of listed eye-relief. You dont quite get the whole fov with your eye against the eyecup, unless you press into it a bit. If you fold the cup down, then youre right on the glass. The eyecup is short as it is, but the EP would be better if that eyecup was just a tad shorter still. Otherwise, it performs just like a good Nagler should, and it does it without the weight and bulk of all the other 2inchers. I use this EP for over 90% of my viewing time.

This is a solid eyepiece. Contrast and edge of field sharpness are on par with Tele Vue excellence. This is a keeper.

Ive had only 2 sessions with this EP so far but can see already that it will be my default wide field choice for use with my NP101. Until now I have been using the 24 Panoptic which is a tough act to follow. The 20mm T5 gives the same true FOV as the 24 Pan but at a higher magnification and with the renowned Nagler space walk experience. When compared to the 24 Pan it is like watching a big screen TV. You see the same show only larger and clearer. Scanning the Milky Way with this EP is simply stunning. The field of view is sharp all the way to the edge and the contrast is very good. The 12mm ER is ample if you do not wear glasses and I see no problems with black-outs or kidney bean effects (as with some of the T4s). At 1 lb it does not present a significant balance problem. This is one great EP. I wont be selling my 24 Pans (I use them for bino viewing) but for single eye wide field viewing in this range the 20mm T5 will most definitely be my workhorse.