Apple finally joined other smartphone makers in 2014 by increasing the size of the iPhone 6. In 2015, Apple made slight changes to the iPhone 6 with the iPhone 6s, but kept the same design. Are the small upgrades to the iPhone 6s enough to make it worth a buy?

The iPhone 6 was updated in 2015 with the iPhone 6s, but only the camera and the new 3D Touch features were noticeable, TechRadar reports. Let's take a look at the two phones side-by-side.

The big difference in the iPhone 6s is the brand new Apple A9 processor. This processor is actually up to 70 percent faster than the iPhone 6's A8 for general use and up to 90 percent faster for graphics processes. This leads to much faster app openings in the iPhone 6s.

The iPhone 6 is actually lighter and thinner than the iPhone 6s. The iPhone 6 is 6.9 mm thick while the iPhone 6s is 7.1 mm thick. The iPhone 6 weighs 129 grams while the iPhone 6s weighs 143 grams.

The camera in the iPhone 6s improved to 12 megapixels (MP) after being stuck at 8 MP for years. However, not much improvement can be seen in photo quality between the 8 MP camera in the iPhone 6 and the 12 MP camera in the iPhone 6s.

A brand new feature called 3D Touch allows users to apply different amounts of pressure to the iPhone 6s' screen to get different results. This is one slight advantage to the iPhone 6s.

Battery life is always an important feature with a smartphone and Apple actually went backwards with the iPhone 6s' battery life. The iPhone 6 has an 1810 mAh battery, while the iPhone 6s has an 1715 mAh battery. With the smaller battery, the iPhone 6s gets less battery life than the iPhone 6.

With the price dropping on the iPhone 6 and longer battery life, the iPhone 6 is the better option, unless users insist on having the 3D Touch feature and the newest phone.

The iPhone 6s currently sells for $649, while the iPhone 6 has dropped to $549.