I'd agree with Dan on that one as well, it really is a question of taste and what kind of record they were making. Jay Graydon doing pop records on Al Jarreau and the like, they're looking for something that hits - bright and cuts through, rather than a mellow, laid-back sound.
Headhunters would have sounded way different on the E Rhodes. Pop records may not have sounded all that great with the Headhunters Rhodes. So I feel it's a bit of give and take on application. I have a '71 suitcase similar to the E (which is why I bought it) and I can definitely hear the similarities, and it's a great sounding Rhodes with a unique character. What I can say is that with the treble all the way up, it actually dwarfs the bass, unless you back off some treble or raise the bass as well.
I'm wondering if the E actually has a preamp EQ mod. It can definitely be achieved with a graphic / parametric EQ - I just believe most people don't know how to dial in the sound they want... it takes an understanding of the Rhodes sound and what frequencies should be amplified or cut. So if a preamp supposedly gives an improved default choice, I think people gravitate to that.