Hi Ryan,
Well I can only agree in part with Brian's comments above.
I agree that "good" orthos or other minimal glass eyepieces like Zeiss orthos, Astrophysics SPL, TMB Supermonos, Pentax XO's, Pentax XP, Pentax .965 SMC, Nikon .965, etc are unsurpassed as planetary eyepieces. Sitting just below them are other excellent minimal glass eyepieces like Brandons, Clave Plossls and Carl Zeiss Jena .965 orthos. The cheaper orthos like Baader, University Optics (both HD and volcano tops), and Circle T etc etc are excellent eyepieces, but not quite to the same level as the premium orthos.
While the differences in many cases are subtle and very marginal, in a good telescope under good conditions, a skilled observer can pick the difference between the "premium" orthos and premium widefields like Pentax XW's and TV Delos. However the premium widefields IME perform just as well as planetary eyepieces as the cheaper orthos like the Baaders and UO HD's and volcano tops. The major difference is that the long eye relief of Pentax XW's and Delos makes them more comfortable to use for long periods.
My current short focal length eyepiece collection consists of:-
5mm Pentax XW
5mm UO HD ortho
6mm UO HD ortho
6mm TV Delos
7mm Pentax XW
7mm UO HD ortho
8mm TV Radian
8.5mm Pentax XF
9mm UO HD ortho
10mm Pentax XW
I own 3 premium newtonians, a 10", a 14" and an 18" and through my association with 3RF Australia I have full access to 20", 25" and a 30" Newtonian.
I previously owned a 5mm Pentax XO, which I sold, as I preferred to use my 5mm Pentax XW based on its very close performance to the Pentax XO and increased eye relief and comfort. This made it much easier to use for extended observing sessions. What I find is that my most used eyepieces for planetary observation are my 5mm and 7mm Pentax XW's and the 8.5mm Pentax XF. While the 5mm Pentax XO slightly outperformed the 5mm Pentax XW the difference was very marginal. When you consider the eye relief and comfort factor I reached for the 5mm XW every time over the 5mm Pentax XO. I find that the on axis performance of the UO HD's is very close to my Pentax XW's (if not slightly inferior) with the edge of field performance in the orthos notably inferior. When you consider the eye relief and comfort factor the orthos don't get a look in. In fact, apart from a recent review I conducted they haven't come out of the case in quite a few years. I keep them for sentimental value only.
Knowing what I know and having used just about every premium and budget eyepiece made in the past 30 years (from Chinese Plossls to 12.5mm Docter {$1,000 each}) I would be jumping all over that 7mm Pentax XW advertised in the Icetrade Classifieds for $265 posted. I would jump on that cause it won't last long.
http://www.iceinspace.com.au/forum/s...d.php?t=118074
The 7mm Pentax XW will give you about 170X in your 10" Newtonian which is an ideal power.
Cheers,
John B