Here's our breakdown of how the iPhone 6 stacks up against the iPhone 4. 

Pros and Cons of the iPhone 6:

The iPhone 6 has a much larger display, lesser weight, and more power than the iPhone 4. At 6.9mm it is much slimmer. It has better camera lenses, a more powerful CPU, and availability in larger storage options. Besides, the iPhone 6 has Siri, which is absent in the iPhone 4.

The iPhone 6 is the latest model in the series and doesn't seem to have any con that may go against it in comparison to the iPhone 4. But when compared to other ace smartphones in the market, Apple could have improved it by adding more powerful cameras, CPU, and an expansion slot.

Pros and Cons of the iPhone 4: 

The only advantage the iPhone 4 may have over its larger brother is that it is much cheaper. Otherwise, it is 5 years behind.

The iPhone 4 has a smaller display compared to the current-generation smartphones. It has a 1GHz CPU, only 512MB RAM, and 5MP primary camera. It is smaller than the iPhone 6 but thicker and heavier. The maximum storage option available is for the 32GB model.

Specs:

The iPhone 6 is Apple's current flagship smartphone, which features a larger 4.7-inch, LED backlit IPS LCD display with 750x1334-pixel resolution at 326 ppi. Powered by iOS 8, the smartphone has a 1.4-GHz dual-core A8 at its heart. The OS can be upgraded to iOS 8.1.1. Other main attractions in the iPhone 6 include an 8MP primary camera, 1.2MP front-facing camera lens, 1GB RAM, Siri, and 14 hours of talktime. The phone measures 6.9mm in thickness and weighs 129g. It is available in three storage configurations - 16GB, 64GB and 128GB without any expansion slot.

The iPhone 4 features a 3.5-inch LED backlit IPS LCD display with 640x960 pixels @ 330ppi. It was initially launched with iOS 4, and was later made upgradeable to iOS 7.1.1. It has a 1GHz Cortex A8 processor, 512MB of RAM, 5MP rear and VGA front camera, and 14 hours of talktime. Other features include 9.3mm thickness, 137g weight and availability in 8GB, 16GB and 32GB storage configurations.

Talking Points:

The iPhone 6 was released in September 2014 along with its larger phablet version, the iPhone 6 Plus. The iPhone 6 series broke Apple's all previous records for sales. More than 4 million phones were booked in pre-orders, and a staggering 10 million were sold within the first 3 days. The smartphone received mostly positive reviews. It was praised for its "brilliant" design by TechRadar. It was the "best smartphone" according to Re/code. The Verge pointed it out to be "cleanly designed."

The iPhone 4 was unveiled in June 2010 and released the same month. It may be thicker by the current standards, but at the time it was the "thinnest smartphone" according to Apple. The phone was a major success for the Cupertino firm, recording 600k pre-orders and over 1.7 million sales within the first 3 days. Three years later the company discontinued the model after releasing the iPhone 5 series. However, the iPhone 4S took its place.

Prices:

The iPhone 6 comes with an outright purchase price tag of $649. The Apple iPhone 4 is currently unavailable, since it had been discontinued and replaced with the iPhone 4S. The 4S costs around $292.90 on Amazon.

Conclusion:

The iPhone 6 is easily the smartphone of choice between the two. It is the latest generation phone with a larger display, more powerful CPU, better camera, iOS 8.1 operating system, more RAM, 128GB largest storage option compared to the iPhone 4's 32GB, and a Fingerprint sensor. You can, however, have an iPhone 4S, a later version of the iPhone 4 for just $292, more than half the price of the iPhone 6. But it will not be worth it.