It was a safe bet that Apple’s latest flagship iPhone (News – Alert) would be a hit, but this time around its popularity has reached unprecedented levels. For example, an elusive gold iPhone 5S went for a little over $10,000 recently on eBay (News – Alert). This time, though, the iPhone’s impact is expected to be greater than ever as it comes with the most significant iOS update yet.

While iOS 7 boasts a lot of clear improvements over past versions of Apple’s (News – Alert) mobile platform, its handling of HTML5 is shoddy, according to a Sencha blog post. In fact, the post goes so far as to say that the number of bugs and broken features in iOS 7 make it seem more like a beta release than a final version, leading to the recommendation that organizations which deal with HTML5 development wait to upgrade.

To be fair, iOS 7 does sport some “impressive performance gains” in SVG and JavaScript, but the positives seem to end there.

On the negative side, iOS 7’s Web runtime is hobbled by a few significant issues. First, the ability to modify WebSQL permission to increase default app space from 5MB to 50MB doesn’t work without a workaround. Second, Save to Home Screen apps are also broken, with problems occurring after more than four apps are saved to the home screen. Meanwhile, external URIs don’t open correctly, all JavaScript modal dialogues are disabled, and apps using AppCache that manage state with hash or other mechanisms won’t see their history object update.

Major bugs aside, iOS 7 seems to also take some steps back in terms of design and usability. For starters, it’s no longer possible to hide the URL bar with JavaScript, while the full-screen option is no longer available in Safari. Another issue is that right and left swipe gestures close to the screen’s edge are treated as forward/back requests by iOS rather than being handled by the browser, leading to unexpected behavior in pages that have built-in forward/back functionality.