If you haven’t updated your iPhone 6/6 Plus to the recently-released iOS 9, I’d suggest you hold off for a few weeks. Several bugs – including a significant security hole – have surfaced that will take Apple some time to address.

The security bug in question allows an unauthorized user in possession of your phone to access your contacts and photos, even if your phone is locked. The whole process is remarkably uncomplicated and requires no computer expertise. Considering the simplicity of this “hack” and how quickly it’s been spotted by third-party security testers, I have some concerns about Apple’s own security testing methods.

Currently, there is no fix for this problem, other that disabling Siri access from the lock screen, which, obviously, renders Siri less-than-useful.

Personally, I’ve noticed significant sluggishness in the new app switching functionality on my 6 Plus. I wish I could remove the useless app previews and go back to the old icon-style app switcher.  Some people may like it, but, in my opinion, it adds no new functionality and, obviously, taxes system resources.

Another new annoyance has to do with screen rotation: sometime the home screen rotates for no apparent reason and refuses to rotate back until you swipe between pages. I know Apple’s been tinkering with screen rotation lock feature. Perhaps a bit more tinkering is in order.

Additional bugs in iOS 9 have been identified that may give you a major headache if you use your iPhone to connect to your office. This is probably the more significant issue for people using their iPhones for work. You should definitely check with your IT department to see if upgrading would cause connectivity issues.

Not to appear overly negative, I did notice improved performance from Safari. A good test is to browse a Tumblr page with a lot of photos. This can bring even Chrome running on a powerful desktop to its knees. So far I’ve seen none of the previously-commonplace Safari crashes. The improvement has to do with better memory management by the OS, so some folks at Apple are clearly doing their work right.

As a Unix SysAdmin, my credo is “if it ain’t broke – don’t fix it”. For that standpoint, I’m glad to see Apple concentrate on small system-level and small functionality enhancements, rather than the iOS 8’s mindless avalanche of buggy “feature” nobody asked for.

Ultimately, to upgrade now or to wait a little is your choice. Apple did fix a number of security issues in the new OS. Unfortunately, new bugs are inevitably introduced. Any upgrade is, essentially, a process of replacing old know bugs with new and exciting ones.