This eyepiece is amazing in so many ways. I usually don't get to observe until after work or after other commitments are satisfied so my main objective when I step out for an evening is to relax. Everyone knows about the 20mm of eye relief but these oculars have some other features that really make them worthy additions to your accessory kit. The lack of pincushion distortion and blackouts put these at the top of the list for ease of use. An added bonus is the excellent contrast and light throughput. Better than any multiple-lens widefield I know of. Downside, besides the price? The bulky Michelin-man profile may use up valuable real-estate in your eyepiece case quickly and edge-of-field performance I would just rate as good in fast scopes, (instead of great. But these are all trade-offs I gladly make for the comfort and excellent performance of the Pentax name!