Here are a few reasons
A great no fault life time warranty! If it needs to be repaired or it fails in the field, send it back and have Explore Scientific repair or replace it!
Water Proof! No your not going to use it in the rain or take it swimming, but what if you did get caught in the rain, or it became covered in dew, or even worse you went and cleaned it and the cleaning solution got into the eyepiece and between the lens??
With Explore Scientific eyepieces they are Argon purged to keep out moisture and o-ring sealed. This will keep out all of the stuff that does not belong between the lenses.
With Explore Scientific you get fantastic views, life time warranty, waterproof and the quality and support you would expect. Best of all they are much easier on your wallet!!
Watch this video, which is a little old, but scroll to the 7:35 mark. you will be amazed!!