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Perhaps another thing to consider when looking for a planetary eyepiece would be exit pupil. Something good would be around an exit pupil of 1mm, which translates on the 10" Dob to around a 5mm eyepiece. Not great for DSOs which benefit from exit pupils above 2mm.
Given eyepieces are quite a personal thing it's best to try before you buy as everyone suggests. For me I find eye relief more satisfying than a super large field of view (for me 70° is just great) and this isn't because I wear glasses. The first time I looked through a Pentax XW 7mm at Jupiter I was completely gob-smacked and I owned and was very familiar with the comparable 6.7mm ES82°. I don't think the view was necessarily that much better but something about the large un-recessed glass surface area of the Pentax appealed instantly. So I guess in trying eyepieces as much as you consider magnification and field of view also see if extra eye relief appeals :-)
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