As you may have heard by now, Apple has refreshed its iPad line-up, not only upgrading the 9.7-inch device with the launch of the iPad Air, but also the smaller 7.9-inch device - with the iPad mini with Retina display.

With the iPad mini only being a year old and a design that's still fresh, could it really be worth the upgrade? Or put another way, if you're thinking of buying an iPad mini, which should you opt for: the regular iPad mini, or the iPad mini with Retina display?

We take a closer look at what new features have been brought to the new iPad mini Retina display and what will be staying the same. In short, what's the difference?

The new iPad mini brings Retina display

One of the iPad mini's biggest criticisms was its lack of a high-resolution display, but Apple has changed that with the new iPad mini with Retina display.

The original iPad mini has a resolution of 1024 x 768 pixels, which provided a pixel density of 163ppi, but the new iPad has a Retina display in tow with a 2048 x 1536 resolution and 326ppi, the highest resolution around for a tablet this size.

Almost inperceptable increase in thickness

The introduction of the Retina display has resulted in the thickness and weight of the new iPad mini increasing slightly compared to its predecessor, although in real life it's going to be an inperceptable change when it comes to size.

For those counting, the original iPad mini measures 200 x 134.7 x 7.2mm, while the iPad mini with Retina display comes in at 200 x 134.7 x 7.5mm so you'll see a a 0.3mm increase in thickness.

In terms of weight, the iPad mini with Retina display will weigh slightly more than the original model, hitting the scales at 331g compared to 308g.

Same rear look and elements, new colours

If you were expecting a complete redesign for the iPad mini with Retina display, you will be disappointed, as aside from the tiny measurement differences, the design will be just as it was.

All the buttons and elements will remain in their original positions and you'll see no change on the rear or front of the device, except the colour.

The new iPad will come in the same space grey as the iPhone 5S is available in, as well as silver. There were rumours suggesting we would also see the gold colour from the iPhone 5S appear, but this proved to be a myths.

The camera remains the same

Despite rumours claiming the iPad mini with Retina display would be coming with a camera upgrade to an 8-megapixel rear snapper, the new iPad mini will be sticking with the 5-megapixel rear iSight camera found on its predecessor.

The rear camera will come with an f/2.4 aperture and will be capable of full HD video recording, plus it also brings with it the same autofocus, face detection and backside illumination features found on the original iPad mini.

In terms of the front-facing camera, the iPad mini with Retina display will be sticking with what it knows here too, with a 1.2-megapixel camera which can record video in 720p.

The iPad mini with Retina display will be much faster

As you would expect, Apple has upgraded the processor from the dual-core A5 chip found in the original iPad mini, but what may have come as a shock is it hasn't upgraded to the A6X chip, instead the new iPad mini with Retina display leaps to the A7 chip found in the new iPad Air and iPhone 5S.

The new processor will mean the iPad mini with Retina display will be four times faster in CPU performance and eight times faster graphic performance than the standard iPad mini.

Battery life stays the same, storage options increase

The battery life on the iPad mini with Retina display promises to deliver up to 10 hours of browsing the internet, watching video or listening to music, which comes in at the same as the original iPad mini.

In terms of storage options, the iPad mini with Retina display is offered in 16GB, 32GB, 64GB and 128GB models, compared to the original iPad mini which skipped out on the 128GB model. Adding to this, Apple is now only listing the 16GB verison of the iPad mini on the Apple Store.

Both devices also have the usual Bluetooth 4.0 and Wi-Fi on board, and there is also a Wi-Fi and cellular model also available.

The new iPad mini will cost more

The original iPad mini started at £269 for a 16GB Wi-Fi only model, moving up to £529 for a 64GB Wi-Fi and Cellular model. That's now changed, with Apple only listing the 16GB option with a £20 price cut to £249. The 16GB cellular version is £349.

The iPad mini with Retina display will be more expensive starting at £319 for a 16GB Wi-Fi only model, and hitting the £659 mark for a 128GB Wi-Fi and Cellular device, but given the upgrade in processor and display, you might not mind too much. You'll have to wait until some uncomfirmed time in November to get it, however.