For the price vs a dedicated macro lens, it is a no brainer IMHO. Produces very good results with a decent lens underneath it.Yes I am not into Macro much but it would be good to get something cheap as chips to mess about with occasionally...
I've used both the 250 and the 150.
IMVHO the 250 gives too much magnification, I prefer the 150.
http://www.mu-43.com/f38/pany-45-200-fitted-raynox-150-data-pictures-18693/