I'm currently using my Kobo Glo HD most often, but that could just be because it's new
I do like the little bar graph and estimated time you get with kepubs. So I've converted my current reads to kepubs. They're a little bigger than epubs but not much. Is it the Kobo-bought kepubs specifically that are much bigger? Even though I do buy from Kobo I tend to get the ADE epubs for Alf processing rather than kepubs (yes I know it's possible to deDRM kepubs but I use Linux and ADE is easier).
Having said that, I like my PW2 too. And I also use my PC quite a lot using either Calibre or a web based reader.
Ultimately there are bells and whistles but as long as you can find a book, maybe adjust the font size and navigate through it page by page then it's doing it's job. And I think they all do that.