Hi Dave,
I have the Meade shorty barlow and it works very well, BUT........
with a fast "F" ratio scope the shorty will not project the full light cone that a fast scope displays.
So basically your wasting light.
There is a way out though, there are barlows that are made specifically to work with fast (or slow) "F" ratios.
Televue is one brand, but if the $'s don't go far enough for those, I've found another small manufacturer of quality optics in the U.S. called Siebert Optics.
They make different level of optics, but their premium level is the "Ultra" range.
I recently purchased the 17mm + the Telecentic 2X barlow. The barlow comes in different mags and is made for fast scopes. The views are spectacular. They're made in 1 1/4" or 2" sizes and are half the price of the Televue. Weight is kept down by mounting the lenses in aircraft aluminium.
The barlow and e/p weigh just a little more than my Meade 2" 26mm.
Del is about 10days.
www.siebertoptics.com