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I have a 150x1200 refractor, so the same focal length and magnification. I loooove my University Optics 7mmHD ortho for moon and planets, and for about $120 it's relatively cheap. It is razor sharp and I can see surface detail on Saturn pretty easily. Since it was so good I then got the 5mm version but I've found it less useful. Two reasons. The atmosphere doesn't often support 240x seeing (at least not around here) and it is physically difficult to use. Orthos have small to very small eye lenses and short to very short eye relief (the lens to eye distance). Being decidedly 'old school' I don't mind this - when I started in astronomy you had no choice - but the 5mm is hard even for me. These days many people prefer the long eye relief of some of the newer designs and apparently they work quite well even though they have more glass elements (which should be a disadventage). I haven't used one so I can't comment.
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