Days after the iOS 8 release date, users continue to report bugs and crashes with Apple's latest mobile operating system.

A number of irate users have taken to venting their frustration regarding iOS 8 on social media. These complaints tended to focus on iOS 8-related crashes and lag issues.

Apple will likely release future fixes for problems associated with iOS 8. Just to be fair, the previous iOS 7 OS had many bugs on initial release. Eventually, iOS 7's reliability was  improved in subsequent software updates. Users who recently installed iOS 8 can still downgrade their devices to the previous iOS 7.1.2 operating system. OSXDaily kindly provided information on how to do this in their latest article.

Please be aware that downgrading the OS is not possible with the iPhone 6 and iPhone 6 Plus, which comes preinstalled with iOS 8. Ironically, recent iPhone 6/6 Plus sales have boosted iOS 8 adoption by about half, according to 9to5Mac.

Naturally, tech observers have a lot to say about the iOS 8. In the sections below, we will look at the top three issues that have been cited so far.

New Study Suggests iOS 8 OS is More Likely to Crash than iOS 7.1 OS

Recent trials conducted by app performance experts Crittercism showed that the iOS 8 was less reliable than the previous iOS. 7.1 OS. These results were later revealed on BGR.

The study found that the all devices running iOS 8 had a 3.56 percent chance of experiencing app failure. In contrast, the iPhone 6 and iPhone 6 Plus had much better percent averages when factored alone. The iPhone 6 running on iOS 8 crashed 2.63 percent of the time, while the iPhone 6 Plus on iOS 8 had a crash average of 2.11 percent.

Even so, both iPhone 6 variants performed worse than devices running iOS 7.1, which only had a 2 percent crash rate.

16GB iPhones May Not Have Sufficient Memory for iOS 8

A day after the iOS 8 release, Forbes listed eight issues with the software. One problem was with the space required for an upgrade. According to the report, some people reported needing up to 7GB of free space when installing the iOS 8.

This will be a problem for those who purchased the 16GB version of the iPhone 6. Many users will need to delete apps in order to make space. Luckily, a backup copy of the music library can be made on iTunes. Hence, 16GB iPhone owners will need to manage their internal storage a lot stricter when operating iOS 8.

Bugs Are More Serious on the iPhone 4S

Unveiled for the first time at WWDC 2014 in June, iOS 8 introduces more than 100 new features. Officially, any Apple products from iPhone 4S onward is getting the new update. However, iPhone 4S users may want to consider skipping the iOS 8 OS entirely due to a number of issues.

The phone uses hardware that is simply not optimized for the iOS 8. For instance, the iOS 8 is designed for mobile devices with larger screens. The iPhone 4S has a 3.5-inch screen, whereas the iPhone 6 has a 4.7-inch screen.

As a result, the iOS 8 introduces speed and rendering issues to the iPhone 4S. This information was confirmed in an article by Ars Technica. Also, iPhone 4S users will miss out on many features that are supported on iOS 8 such as Touch ID and Apple Pay.