First, I have to admit that I have never heard the M97XE, so I can't comment on it either way.
That being said, I have several M91EDs (4 to be exact) and a couple of M91Es (an earlier version of the M91ED with a different mounting bracket.) They are a great sounding cartridge that can be had for around $30 or so shipped (less stylus) if you keep your eyes open on the big auction site. It sounds great with a cheap EVG generic stylus (about $15 or so shipped from several sellers on that aforementioned auction site), so for less than $50 total outlay, you are ready to go. And if you decide you really like the cart you can upgrade to a JICO SAS stylus (about $130 or so if I recall correctly) for sound that matches or is better than much more expensive carts. It has been said that it punches way above its' weight class. I have to agree. It would be really hard to go wrong with the M91ED.