What is the deal here?

SEBZxELITE

So heres the deal, I wanted to spend around £300 on a bike and found the 520 which was only about £30 over my budget but then the 540 went on sale and I think i might as well spend the extra £20 if its worth it. However I fail to understand the difference between the two bikes :?

http://www.decathlon.co.uk/rockrider-540-mountain-bike-id_8293149.html

and

http://www.decathlon.co.uk/rockrider-520-mountain-bike-id_8293188.html

Thoughts? Is the 540 even better? the 520 has better reviews but im no professional

BloggingFit

Some mildly better components on the 540.