With 20 million Chromecasts already sold, there's a fair chance you've already got one. Google's dinky streaming dongle has proved a hugely popular alternative to more expensive set-top boxes like the Apple TV and Amazon's Fire TV.

If you don't own an app-enabled smart TV already or want to quickly screen what's on your phone or tablet, then the Chromecast is already a great purchase. So what's different about this new puck-shaped model, and do you need to upgrade?

In the space behind the TV, no-one can see you stream

The old Chromecast was a thing designed by engineers, and as a result it looked like a chunky USB stick. The new model is a much more exciting neon biscuit. This is, however, unlikely to make any difference to you. You'll only see it once, when you take it out of the box, and then it's behind the TV. It could have a picture of a naked Patrick McGoohan on it for all you care, because it'll remain out of sight for its entire working life.

There's no place like chrome

As with the previous Chromecast, plugging in and setting up takes about a minute. It still needs USB power, but it'll run on the 5V from a regular USB socket, which your TV almost certainly has. The original Chromecast was set up through a browser, but this time you use the app.

It's in the app that you get a look at the way Google wants you to use its Chromecast: different services are gathered into the same app, making it a hub for all the possible things you can play. This hasn't been implemented outside of the US yet but when it has, you'll be able to simply type 'Paul Rudd' into the Chromecast app and then take your pick from Paul's array of reliably funny films on Netflix or iPlayer, or watch clips of Paul's masterful chat show appearances on YouTube.

The fast and the few-more-metres

The new Chromecast is faster. Loading a new show or episode isn't instantaneous, but it still manages to start streaming a Netflix episode faster than most websites load on a phone. After loading 20 or 30 programmes we'd say the waiting time has halved, but it's halved from about eight seconds - so you'd have be an incredibly impatient person for this to matter.

More importantly, the Wi-Fi reception has also improved. If you've tried a Chromecast in an upstairs bedroom and found it unable to reach the router, the new one could well solve that problem - unless you've got a really massive house, in which case you can probably afford some powerline extenders.

Citizen Game

Adding to the new Chromecast's charms are the fact that you can use your phone as a games controller - a semi-proper one, rather than a mirrored display. This makes gaming a lot easier because the controls can be larger on your phone's screen, but it's not on a par with the sort of Android gaming you can do on the Nexus Player, with its dedicated controller and separate processor.

The best games for Chromecast are the ones that acknowledge that your phone is a flat screen and use it as a secondary display, like Scrabble Blitz and Monopoly Dash.

Who framed all the rad-pics?

The last item on the new Chromecast's list of attractions is the new Google Photos integration, which adds some nice big-screen display options to a great app. If you're fed up with looking at the brilliant default but perhaps over-awesome photography your old Chromecast was displaying as a screensaver, you can now set it to show your Falliraki '14 Lads On Tour album whenever it's idle. Those memories will last a lifetime.

Chromecast (2015) Verdict

So, should you get one?

If you already own a Chromecast and you're wondering if you need to upgrade, then the answer is no. If you want to play Android games on your TV then you'll have more fun with the Nexus Player. If you can't stand the eight seconds it takes the original Chromecast to load a TV programme then you need to try some breathing exercises.

But if you don't have one - or if you're looking to turn your bedroom TV into a smart, game-capable Netflix machine - then this is a seriously brilliant and highly affordable device.

Stuff says... 

Google Chromecast (2015) review

The new Chromecast is simple, smart, works brilliantly and is cheap. What more could you ask for from a gadget?
Good Stuff 
It's fast and has superior Wi-Fi
Simplicity, great app
Cheap as chips
Tons of apps work with it
Looks nice
Bad Stuff 
Still waiting on some functionality
Some apps and games are yet to catch up