[nathanlrivera]

1. It just works - I have never encountered an issue with the bookmarklet not formatting an article correctly.

2. Day vs. night mode. You can configure it to automatically switch to white text on a black background at night.

3. Performance - even with 100+ articles the app doesn't slow down and downloads new articles in seconds. Switching between articles and scrolling long articles is liquid smooth.

Overall, you can tell just by using it that a ton of thought was put into the UI.

[rubergly]

I agree that instapaper is fantastic, but the article formatting only works for me about 95% of the time. There seem to be some sites that it occasionally gets wrong in a really annoying way (like including some odd dump of the site's sidebar that requires you to finger-swipe for about 5-10 seconds on an iPod to get to the article contents, which are of course easy to speed by).