DSC-F717 lens adapters

I am pondering whether to purchase any of the DSC-F717 lens adapters (cf.
http://www.dpreview.com/reviews/sonydscf717/page4.asp), and I have a couple
of questions for anyone that might have tried them or otherwise have
knowledge about these.

1) Both wide-angle adapters are 0.7x but seem to have different physical
characteristics, namely one appears considerably smaller than the other.
Which of these is better? Which gives more vignetting, etc?

2) As for the 1.7x telephoto adapter/extender, I already own an Olympus
B-300 I plan to use instead with a 58-55mm step-down ring. Anyone know how
much vignetting the Sony 1.7x produces and/or whether it is any better glass
than the Olympus?

 

On question 2, I found the following quote from an old posting:

"The Sony VCL-HGD1758 is an
exceptionally good telextender and does not vignette until from about
60% of the zoom range to full telephoto, much better than say the
Olympus B-300 that I have which will vignette at all settings up to
about 75-80% of the max telephoto setting."
http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&selm=010820031529102157%