everyone has preferences as to what they find visually pleasing whether it's skewed to warm or cool. The Hero and the Moment are skewed in different directions. Regardless of their different technologies, the screens can also be calibrated to compensate and make them more neutral. Heck, AV installers make a living out of it. Companies make products to do it as well. There's no reason why phone companies can't do the same. If their screen pushes a color over others, then they can tone it down and bump up the others to compensate. I only wish I knew why it hasn't trickled down to these touch screen devices yet.
That being said, there is a difference in the screens if you hold them up side by side with the same content. So it comes down to which one you prefer. If it was me, I would prefer the Moment if I was more media oriented. But I care more about how clean black text looks on a white background, and I prefer the Hero's screen. I have both phones and have used them extensively. For me it strictly comes down to typing. I truly don't care for on screen typing no matter how much I do of it. I had the Hero with me for my New Year's trip, and it was just reinforced. I like having more screen real estate while I'm typing. I type more intuitively on a real keyboard as the touch typing skills learn the keyboard layout, and I can take my focus away from the keyboard. So all the other diffrences aside, it's the one thing that affects me most on a daily basis.
I also think HTC and Sense add a lot to the "smartphone experience" where vanilla Android fails and 3rd parties fall short or just add way too much lag. If the kernel update helps there, great, but I still don't like relying on 3rd party software for some things I think should be built in like T9 dialing. The phone part of Android is laggy enough as it is. It's the least crisp of any phone I've ever used, and programs like aContacts that add T9 severely add to the lag. Having it built into the Hero makes it much smoother.
Of course people here will be defensive about their purchase so you'll see things skewed towards the Moment. But in the end, both phones have merits and drawbacks. Many of them personal and not universal. So take everything with a grain of salt, read forums and reviews for both to figure out which one you'd like to try first. You've got 30 days to essentially give both a shot and see which one works best for you.