I have been reading The Financial Times and The Wall Street Journal on my KT. I think the call is subjective - the screen IS smaller than the iPad, after all, significantly - but I find it to be a pleasant experience. I use the menu to find the articles I want to read (rather than scrolling the section header pages like I would on an iPad) and, once reading, I don't notice the difference. So, I guess, where the difference is noticeable is in the browsing stage, rather than in reading. Of course, you don't get the cool multimedia interactive graphs that WSJ and FT push now on the iPad.
Frankly, I like it much better than reading on the iPad - and I pay for the subscriptions DESPITE having free access to the iPad version (paid for by my employer). The main advantage (aside from the portability of the device and eink) is that the issues are delivered overnight, so you don't get the pauses that you experience when reading on the iPad, as it pulls content from the WSJ and FT apps.
I use my iPad for PDFs as well - but that is very different reading. I could not take PDF on 6 or 7" screens, but I am perfectly comfortable with newspapers.
Currently, I use my KT or my SONY PRS950 for newspapers and books. My iPad for PDFs.
By the way, I did not mention it, because you probably won't have that option anymore (unless you find a used one on ebay) but the SONY PRS950 is a better solution for newspapers than the KT. The 7" screen is not much bigger, but the extra space makes for more comfortable browsing and file management of periodicals is more straightforward. If you can find a used one, I would recommend it.