Originally posted by clockwork247 i'm probably getting the 150 then...
i think it'll be enough for me.
The DCR 150 is a good choice for the DA(L) 55-300 as you'll have adequate working distance (about 8"), at least up to 1:1 mag*.
Another important feature is the on-board camera flash will continue to work automatically, at least out to about 1:1 magnification. I think the lens gets in the way of the flash when the magnification goes much above 1:1 but that can be corrected by using a piece of white paper as a reflector.
Having the flash work is important as lighting is problematic for macro work due to the high f-stops needed for adequate depth of field. The 250's shorter working distance will put it in the DA 55-300's shadow at a lower magnification.
Dave
* A useful equation for working distance, w, at constant focal length is: w'/w = (1+1/m')/(1+1/m)
so going to m=2 from m=1 by extending a lens decreases working distance by a factor of (1+1/2)/(1+1/1) = 0.75