I originally purchased a pair of Shure KSM109s... which BOTH turned out to be defective... since there were no more KSM109s in stock, I opted to try out an Audio Technica AT3032. Slightly more expensive than the Shure's I originally purchased, but more than worth it!
Transient response is much better as is frequency response! The KSMs had a slight bass roll-off, the ATs don't. ATs also capture highs much better than the 109s did (when they weren't crackling)
I do wish I had a chance to try the KSMs in their full working glory... but I'm glad I gave the Audio Technicas a chance.