I agree, get more memory than you think you will need, it is amazing how easy it is to fill it up especially with music and you don't want it to slow down as you add more data as Rebecca pointed out. I do like the cloud for music, don't know how well it works to stream music to your Kindle from the cloud or if it is better to store it on the device (I stream it from the cloud to my Samsung Note II phone). I've been considering getting a Nook HD or other tablet for the same reason you are considering - though to be truly useful for me for work I would need to find a device that I can use a Citrix VPN connection to my computer at work. I suspect that would have to be a Windows device and I don't know that I am willing to do that. I DO like the non-glare screen of my basic Nook device, and the battery life just rocks.

I think those are all great reasons to get the device, good luck with your decision! I've been building up my home gym or I would have already pulled the trigger on something like this.