Apple once resolutely claimed that a 3.5in screen was the perfect size for a smartphone. That was until two years ago when it launched the 4in iPhone 5 claiming that was the ideal smartphone screen size.

We're not sure what Apple is claiming now, but it has just launched the iPhone 6 with a 4.7in screen, and the iPhone 6 Plus with a huge 5.5in screen.

iphone 6 iphone 6 plus
The iPhone 6 and the iPhone 6 Plus. Apple

While Apple is new to this phablet market, Samsung is the company credited with creating it, and it has just launched its Galaxy Note 4 smartphone which boasts a 5.7in screen.

So, which is better, and if you are in the market for a big smartphone, which should you buy - the Samsung Galaxy Note 4 or the Apple iPhone 6 Plus?

iPhone 6 Plus vs Galaxy Note 4: Design

Apple has built its smartphone reputation on using premium materials and employing sleek, minimalist design - and the iPhone 6 Plus is no different.

At 7.1mm thick the iPhone 6 Plus is certainly slim, although we've yet to find out just how much it weighs compared to the Note 4's 176g.

The iPhone 6 Plus will be available in space gray, gold, or silver.

The Galaxy Note 4 sees Samsung beginning to move away from using all plastic in the construction of its flagship devices, with a real aluminium frame used here.

The Galaxy Note 4 has a more squared off-design and it is 8.3mm thick. The rear cover is still made of the same "leather-like" polycarbonate material as the last Note, but without the faux stitching.

The Galaxy Note 4 is available in white, black, gold, and pink.

iPhone 6 side view
iPhone 6 side view Apple

iPhone 6 Plus vs Galaxy Note 4: Screen

The iPhone 6 Plus screen is 5.5in and has a resolution of 1920 x 1080, giving it a pixel density of 401 pixels per inch (ppi), which is slightly higher than the iPhone 5S.

It is covered with ion-strengthened glass, meaning that it should be much more resistant to scratches and cracks.

The Samsung Galaxy Note 4 has a 5.7in screen with a Quad HD resolution of 2560 x 1440 pixels, giving it a pixel density of 515ppi, which puts it well ahead of the iPhone 6 Plus, though Apple will argue that users won't be able to actually see any difference.

The screen on the Galaxy Note 4 also features a slight curve creating a 2.5D effect which should make swiping from the sides easier.

Galaxy Note 4: Next-Gen Phablet's Super AMOLED Screen to Produce Super-Accurate Colours
Galaxy Note 4: Next-Gen Phablet's Super AMOLED Screen to Produce Super-Accurate Colours

iPhone 6 Plus vs Galaxy Note 4: Hardware

Apple is typically reticent about the specifics of its smartphones and tablets, such as clock speeds and gigabytes of RAM, and the iPhone 6 Plus is no different.

What we do know is that the iPhone 6 Plus will use Apple's all new A8 chip which promises to be as powerful as anything else on the market at the moment. Apple claims this chip is 50% more powerful than the A7 found in the iPhone 5S.

Apple has also finally added NFC to facilitate mobile payments, and is now offering a 128GB storage option to hold all the films you are going to watch on that bigger screen.

Apple has also included the Touch ID fingerprint sensor which was first seen on the iPhone 5S.

The Galaxy Note 4 is available in two versions, one powered by a quad-core 2.7GHz Qualcomm Snapdragon 805 processor while the other will be powered by Samsung's own Exynos 5433 chip. Both models will come with 3GB of RAM.

The Note 4 also features a fingerprint sensor, a heart-rate monitor, and of course Samsung's S-Pen stylus which is one of the big selling points of the Note series.

The Note 4 is available in 32GB or 64GB options with a microSD card slot which can add up to a further 64GB.

iPhone 6 iSight lens
The iPhone 6 Plus boasts optical image stabilisation. Apple

iPhone 6 Plus vs Galaxy Note 4: Camera

The iPhone 6 Plus features an 8 megapixel iSight camera with optical image stabilisation. It supports 1080p recording at 60 frames per second (fps) and 30fps. Slow-motion video can be recorded at 240fps or 120fps.

The Note 4 comes with a 16 megapixel sensor, along with optical image stabilisation and dual-LED flash. There is also a 3.7 megapixel camera on the front which is capable of capturing 1080p video.

iPhone 6 Plus vs Galaxy Note 4: Software

The iPhone 6 Plus will come pre-loaded with iOS 8 when it launches on 19 September which brings with it a host of new features including support for third-party keyboards, interactive notifications, improved maps, and even widgets.

Samsung Galaxy Note 4 S-Pen

The biggest updates however are HomeKit and HealthKit, Apple's home automation and health platforms which will allow the iPhone to become a hub for collecting information from hundreds of connected devices, from wearables to security cameras.

The Galaxy Note 4 on the other hand comes with Android 4.4 and Samsung's own TouchWiz user interface (UI) skinned on top. Samsung has included a lot of apps for note-taking, drawing, and even handwriting recognition to use with the S-Pen.

One new addition is Snap Note, which will allow you to take a picture of a real-world note and within minutes will convert it into a digital note you can edit on your phone.

One thing to consider about the phones' software is that while the iPhone 6 Plus will get iOS updates regularly and automatically, the same cannot be said for the Note 4, which is important with the major Android L update due for release later this year.

iPhone 6 Plus vs Galaxy Note 4: Price

The iPhone 6 Plus will be available for pre-order from this Friday, 12 September, and will go on sale a week later, on Friday, 19 September. The phone will first be available UK, US, France, Hong Kong, Canada, Germany, Singapore, Australia, and Japan.

In the US the iPhone 6 Plus starts at $299 with a two-year contract in the US, rising to $399, or $499 for the 16GB, 64GB, and 128GB models respectively. UK pricing is yet to be revealed.

Pricing for the Galaxy Note 4 has yet to be revealed ahead of its launch in October, but expect it to be in line with the Galaxy Note 3, which was £650.

iPhone 6 Plus vs Galaxy Note 4: Overall

So which should you buy? That's a tough one to answer as each has its own merits.

The Galaxy Note 4 has a slightly bigger screen with a significantly higher resolution display. It also has the S-Pen stylus and lots of apps designed to make the most of it.

The iPhone 6 Plus is new to the large-screen smartphone market but the Apple brand will go a long way in helping to sell a tonne of these phones.

Typically great Apple design, aligned with iOS 8 and that much bigger screen will be a completely new experience for iPhone fans, and it is likely going to be a case of 'wait and see' before they decide which form factor and which platform is right for them.