To the OP:
I upgraded from the Kindle Fire to the Kindle Fire HD, and liked it so much that I sold my iPad (first generation) and have preordered my wife the 8.9" KFHD.
In my opinion, EVERYTHING is better about this upgrade:
*The device itself has a better form factor, and the magnetic case fits like a glove, and is much better than any case they've ever had before. I LOVE just opening it up and it's on, and closing it and it's off.
*The screen is crisper, and because of the way it's built, the text and graphics seem right at the top of the screen instead of seeming to be buried beneath a couple of layers of plastic.
*Everything is faster, and games that I had deleted off the first gen Fire because of lagging work fantastically in the HD.
*The speakers are actually quite good, not just acceptable, but good!
*The biggest reason is intangible: I just enjoy it more, and don't have any complaints about it. I know it's not perfect, but I'm an Apple fanboy, and I sold an iPad to buy a second, larger Kindle Fire HD...that should tell you something right there.
So yes, the upgrade is ABSOLUTELY worth it.