Steve as you know I currently own a 2.5 and 5x powermate. I did have the TV 3x Barlow and the Meade tele 2x.
While the later two were fine barlows they did have their shortcomings. In particular they tended to be a little too bright in my scope and the lack of baffling sometimes produced unwanted ghosting.
From my own point of view I have been very happy with both of the Powermates, although I find that I can rarely use the 5x on the 10" scope due to the large focal length this produces. They are beautifully made and help produce some of the best images of Saturn and Jupiter I have ever seen through and EP. They are also pivital to my imaging of the planets and I would not be without them for this reason alone.
The Meade tele-extender is not a powermate. The Powermates are a different optical design, and produce better images.
They are expensive but well worth the outlay as far as I am concerned.
Hope this helps.
