9 out of 10 points and recommendedImage quality, weather sealing, stabilisation, focus limiterPoor quality at close focus, Price
This lens does indead compare very well with prime lenses. The measured MTF values are very similar to the 100mm macro.reviewed December 10th, 2007 (purchased for $1,200)
The one area where it fails to impress is at its close focus distance. In fact below 5 feet the image quality is very poor - MTF about 1/3 of its value from infinity to 5 feet, effectively useless.
To use the lens for close-up work, simply attach either extension tubes or the 500D closeup lens (via a step-up adapter ring). Either of these methods allow the lens focus to be positioned near infinity and the quality is restored.