Thanks a lot, bimasta; you called me back to my senses. It's rather easy to get lost in the labyrinths after 48 hours of non-stop internet browsing -we all know that dark tunnel here, I'm sure. I agree with your view on audio websites or magazines; and I gather one reads those professional reviews mainly looking for reassurance, but when it comes to making choices we tend to trust much more in our fellow audio enthusiasts.
A couple of things I've realized from this discussion:
1) Perfect impedance match between cartridge and preamp is absolutely not a sine qua non. But it may be the case with these bloody Hana. Take a look at the answer I got in another forum: "the Hana's are greatly effected by impedance , more than any other cartridge I have used. My tube pre only went to 300 ohms and the Hana SL I had tried sounded like crap. I tried adding a step up transformer that had a 500 ohm winding but it still sounded bad. I ended up just selling the SL. So yes, they need the 600 ohm loading."
2) If I'm going with an MC cartridge, it will be a low output one. (But not as low as the DL-304 again).
3) Most of the great opinions about Hana come, indeed, from professional reviewers. The number of actual real-world opinions and praising about them is insignificant compared to, say, what you may find about Denon or AT cartridges.
This is why, on second thoughts, I'm starting to think that the Denon DL-103r (or maybe the DL-301 mkii) would be a much wiser choice in my case -I had ruled it out merely based on one of those reviews! Another interesting candidate would be the Nagaoka MP-200. According to the passionate Ian from HiViNyws (youtube) it's a hell of a cartridge -he actually made a long review comparing the lesser MP-150 with the Hana EL, and declared the former to be better in almost all respects.