My last trial on [tag]Pageflakes[/tag] was sometime ago, see my post here. By early October they have launched a new interface, I have to say it looks a lot better and user friendly. It's on par with Netvibes that I prefer.
The feeds import using OPML file was smooth, your feeds will be stored as bookmark such that you could transfer them, one by one, to tabbed pages you create. The OPML file was exported from [tag]Netvibes[/tag] of course. By the way [tag]IE7[/tag], the release version, failed to import that OPML file.
Pageflakes runs OK on firefox 22.214.171.124 as expected but hanged my IE7 a few times. It also suffered resolution issue on fonts after the feed is dragged within a page.
In the master setting of Pageflakes you could choose from open links in 'pageflakes browser', 'new browser window' or 'this browser window'. However for individual feed setting you have another choice of opening link in 'RSS reader' which I guess is the most preferred option. Wondered why I couldn't make one setting for all feeds.