Thanks for the detailed info and NotebookCheck link. Although, last night I found another benchmark site that shows the AMD significantly higher up the list than the 520M -
http://www.cpubenchmark.net/cpu_lookup.php?cpu=AMD+A8-4...
Could you help me understand this discrepancy? I have to admit, frankly, I have no idea what most of the numbers involved mean, and it's possible I am getting confused as whether lower/higher numbers = better/worse... so don't hesitate to shoot me down if I've interpreted that table wrong.
One thing I forgot to add is that the only resource-hungry application (other than possibly the odd video game) I'd be running is Cubase or similar DAW software. I've heard that, due to the nature of multiple tracks/plugins operating at the same time, the more cores you have the better for this particular type of software. Given that the 520m is dual-core and the AMD is (nominally) quad-core, would this be worth taking into account?
There are tonnes of benchmark tests with 3D applications and video-coding software but seemingly none whatsoever with DAWs. This seems strange to me as I'm sure a significant proportion of musicians and PC users would be interested in this information.
Under more casual circumstances I would just opt for the i5 based on your solid advice, but as this will probably be my largest expenditure this year I just want to hammer out all the factors/details as much as possible before making my choice.