(EDIT: the stiffness I reported in the left shift key is no longer an issue. After the first day or two of use it seemed to loosen up. I'm now bumping this review up to five stars to reflect that since my main issue wasn't even really an issue in the end. Original review is below)
In short, this is a great mechanical keyboard for 40.
It does have its issues - the left shift key for example on mine is a little bit stiffer than other keys. This is fine for general typing but if you play any games or use any applications that require frequent use of left shift, your fingers will start to hurt after a while. Not a problem usually but if you're gaming for 2+ hours at a time it might be an issue. I'm not sure if this is the case on other keyboards, either. It could just be mine. That would indicate some quality control issues from the manufacturer though.
Other than that it's great. Not insanely loud for a mechanical keyboard. Once you get used to the key travel you can type quite quietly since you won't need to slam the keys down each time you press. The lighting effects look surprisingly good - I expected it to look too "gamery", but as someone who generally hates RGB and thinks it looks childish I can say that it's not egregious on this keyboard. You can turn the lights down and change the effects you want to suit your taste.
The keyboard follows full UK layout, which is great since a lot of the ones on Amazon UK use different layouts instead. I've been using it for 10+ hours most days for the past month and have seen no fading. As someone who works on the computer for a living and games as a hobby as well, this is really important. Many cheap keyboards have terrible fading issues and I've seen in the past that some won't even last me a few weeks. So far this one is going strong.
Overall, while it has its issues, I like the keyboard. Sure, some software for RGB control would've been great. But that's not something you see at this price point anyway. It does have a long (2m I think - I haven't measured) braided cable, which you'd only expect to see on more expensive models. The bottom of the keyboard has grooves allowing you to lock the cable into three different positions (left, right and center) depending on where you want the cable to come out. The product feels very solid and the included palm rest is a nice touch.
For 40, you really can't go wrong with this. Sure, spending more will get you something better, but for the price this is great