I have a Kindle DX and am looking forward to getting my eDGe this week. I expect to be selling my Kindle DX shortly thereafter. I work almost exclusively with image-based PDFs and need to annotate and multitask as I read, so the eDGe is pretty much the only game in town for me, aside from an ultra-expensive tablet PC like the Lenovo x201. I don't expect the weight to be an issue because I'd mostly have it resting on my desk or my lap anyway.
I created a table comparing features of Kindle DX, eDGe, iPAD and tablet, take a look:
http://u.nu/8snk7