Canon close-up lens: advice needed (1 Viewer)

Hello everybody,
does anybody out there use the genuine Canon close-up lens (500D - 77mm)?
I'd like to get some feedback on the results I may expect to achieve with this kit - I'm planning to use it on my EF 300mm f/4 for the odd macro shots I may get here and there (that's why I'm not going yet to buy a "real" macro lens)
Thank you very much,
Max

I'm told that the genuine article is very good, Max. So, apparently, are the best 3rd party ones. But I can promise you that the cheap ones are terrible.

I got a set of Hoya ones when I first got the 100-400 - Hoya make two or three different ones and these must have been the cheapest model, because they are cra ... er bad word. Not that they were actually cheap, just that my local camera shop ripped me off.

I still have them, used once, if anyone is interested. Will take any reasonable offer. (AU only.)

Buy the Canon one, or research carefully. Or else buy a macro lens: most macro lenses, Canon or 3rd party, are truly excellent.