I have to say, I am really looking forward to the inevitable iPad version of this app. I stopped subscribing to RG some time ago, partly due to running out of room to store my magazines, and partly because I didn't feel that I was enjoying the mag enough to justify spending what I was on the subs.
However, from what I've seen of the app on my iPod, I do think I'd be inclined to re-subscribe exclusively to this electronic version, this really does look like it's going to be great on the iPad. This really is the future for me, and it seems to be just round the corner!
Apart from the UI issues brought up by other users, the only gripe I have with the app at the moment is the lack of a preview of the back issues / new issues available to purchase within the app; how about a full-size preview of the Contents page for each magazine as you select it, just so we can see what content we'd be buying, for each magazine? This way I'd know in advance whether I'm more likely to enjoy the issue that I'm considering buying, or not.