I looked through a 10" f/10 (yes, f/10) Herschel (sp?) at the Laurel Highlands Star Cruise both this summer and the summer before. WAY cool! Superb views and fairly convenient to use (it was mounted more-or-less as a Dob). Only weird thing is that you have to be very careful where you position your head as it may block the light path. Note that the Herschel has no secondary mirror.
Pat
Pat