I would be using it with my FA 80-320mm on a k5 body.

Has anyone had any experience of a Vivatar Macro Focusing 2x converter? if so, good or bad?
I don't have available cash for a Sigma 50-500 or 150-500 so thought about a tele converter. One of these are for sale on ebay for £85 or best offer. The seller has described it as having 7 elements in 7 groups, which reading another thread was suggested as being reasonable unlike cheap tcs that only have 4 elements.
I am aware of the two pentax 1.7x converters on ebay, but can't stretch to the price of them.
Any comments wil be greatly appreciated.

Does anyone know why when i have taken a photo with either the 28-200 or 80-320, that are both pentax fa lenses, on my k5 the image shows up on the screen for review almost immediately yet takes a couple of seconds with any da lenses i have?

Can anyone recommend a reasonably priced flash gun to use with a K-5? I would prefer one with tilt and swivel to enable to bounce the flash off the ceiling or walls.