The 'loitering' capability under the 'chute really drove the design of the weapon. Getting a burnable chute out of the back of rocket motor was quite a trick. The warhead also had to be quite nasty to achieve effects from a missile that was designed not to directly hit the emitter.
Arguably its best feature was when used in tandem with HARM capable aircraft, giving the SAM crews quite a complicated picture. Add in the odd LO platform and some jamming, both stand-off and stand-in and the overall effect was rather good.
The worst feature, especially when not operating in a mixed package was the speed of the thing. More of a SARM than a HARM, to the point that it was easy to arrive over the target well before the missile you fired earlier.
As ever, no comments on the EW side as those elements live on even after the demise of the missile.