The HTC One was one of the best phones of 2013, but that's yesterday's news now that the popular Android smartphone has been replaced with the HTC One (m8).

What's the real difference between the two though, and should you bother upgrading? What about if you are going HTC for the first time, can you get away with opting for last year's model over this year's offering and save a few pennies, or cents? We look at the two HTC phones and see what the difference is between last year's flagship and this year's flagship really is.

The HTC One (M8) has a bigger display, but same resolution

The display on the HTC One (M7) was lovely. It featured a 4.7-inch display with a 1920 x 1080 pixel resolution that offers a 468ppi pixel destiny for those counting. We loved it then and we still now it now. The screen is sharp, the colours punchy, and the viewing angle good enough for you and your mates to all crowd around to watch the latest YouTube viral.

The (m8), or new HTC One, increases the size of the screen to 5-inches, but keeps the resolution the same. That's a drop in pixel destiny, which technically means is isn't as sharp as the M7 but for most people you won't notice the difference in day to day usage.

Neither display disappoints, and ultimately with the M8 you get a bigger screen.

The HTC One (M8) brings a more solid design and different colours

The HTC One M7 looks good, and still holds its own against most of the 2014 flagship devices and the same can be said for the HTC One (M8).

Both models offer a solid aluminium build and feature HTC's now almost standard front-facing BoomSound speakers, however the HTC One aluminium build is a lot more enveloping wrapping around the sides. For those that counting you get 20 per cent more metal this time around and that creates a more stylised and robust experience. The back is also punctured by not one, but two cameras.

The HTC One (M7) measures 137.4 x 68.2 x 9.33mm and weighs 143g, while the HTC One (M8) measures 146.36 x 70.6 x 9.35mm and weighs 160g.

Yes those paying attention will note that the M8 is bigger and heavier than the original however the metal body feels better in the hand and the design. You also get a bigger array of colours that aren't operator exclusives including a Gunmetal Grey, Artic Silver and Amber Gold. We love the Gold model.

Improved rear-facing and front-facing camera on HTC One (M8)

Two heads are better than one right? That's the thinking behind the Duo camera on the rear of the HTC One (M8).

The same UltraPixel sensor with f/2.0 aperture that is found on the HTC One (M7) is also present on the HTC One (M8), but there is as additional sensor above it, called Duo Camera. This lens is for depth perception primarily, and adds a range of features.

The M8 is a better performer: it's faster and performs noticably better.

The front-facing camera has also taken a big step forward with the HTC One (M8) making it a lot better at helping you take that perfect Selfie. The new device comes with a 5-megapixel, f/2.0 front-facing camera compared to the 2.1-megapixel offering found in the HTC One (M7).

HTC One (M8) is faster and will last longer

The M8 is faster in terms of sheer processing power, and comes with a bigger battery to help last you longer.

The original HTC one included a 1.7GHz Snapdragon 600 processor and a 2,300mAh battery with 2GB of RAM. Although the RAM stays the same for the HTC One M8, you get a bump in processor power - now a 2.3GHz Snapdragon 800 and a ever so slightly bigger battery (2,600mAh) meaning you should get to the end of the day rather than just to the moment you need to call a taxi at the end of a night out in town.

The result of that new processor is the device now copes with not only everyday tasks, but also pretty much anything you can throw at it. Not that we found that to be a major problem with the HTC One (M7) but it is noticeably faster in virtually all tasks. You could argue that if you haven't paid with the new M8 you won't know what you are missing, but if you like knowing you have the fastest handset out there, then the M8 is the one to get.

HTC One (M8) moves to nano SIM

The HTC One (M8) is just as well connected as the HTC One (M7) offering the usuals, including Bluetooth, 4G LTE, NFC and Wi-Fi.

Where the two models differ is move to the nano SIM on the HTC One (M8). No problem, just go to your local phone shop and ask them to change your SIM. It's not a deal breaker and they'll have to swapped out in minutes rather than days.

The M8 adds microSD support

This is a fairly big one, and the one that is likely to get content hoarders the most excited. Although the core memory on the HTC One (M8) drops from 64GB or 32GB in the M7 to 16GB in the M8 you do now get the chance to expand the memory yourself with a microSD slot allowing you to boost that storage space back up to 128GB. There is also 65GB of free Google Drive space with the HTC One (M8).

HTC One (M8) brings Sense 6.0 and Android 4.4

Just like many of the recently announced flagships, the HTC One (M8) will come with Android 4.4.2 KitKat from the box.

The HTC One (M8) launches with Sense 6.0, bringing a number of changes and features compared to the HTC One (M7). If you can pick up a HTC One (M7) that's not locked to an operator the Sense 6.0 upgrade is already available, operator versions from the likes of EE are still waiting (at time of writing) so getting your hands on the new OS will make a difference and bring with it a host of new features.

Sense 6.0 is a refinement of Sense 5.5 found on the HTC One (M7). It is slicker and moves HTC's skin forward, but it isn't a huge change and you can read about those changes in a dedicated feature we've put together looking at how much difference it really is.

Conclusion

The HTC One (M8) is a lovely follow-on from the hugely popular and very well received 2013 model. It has a better camera, a better battery, a better processor, better storage, better design, and better software experience.

All that said the HTC One M7 is still a fantastic Android smartphone that shouldn't be overlooked, especially if you are on a budget and especially if you aren't fussed with the bigger screen (it's not that much bigger) or dual camera (it's better but you can live without it).

If you are only half way through your HTC One (M7) contract you'll be happy to know that you've still got a great phone that will serve you well for another year yet.