Netgear n750 overkill for UK 5mb Download Speed Connection which Router

I am very confused about router download speeds.

I am looking at a Netgear N750 or N600 router however the two models only really seem to differ on the download speeds, one quoting 350mbs and the other 450mbs.

Is there any point in having such high transfer speeds when my Internet connection only allows a wired download speed test of 5mb per secs?

I am with Sky Broadband UK.

All I am really worried about is best possible coverage around the house and high speed balanced with a reasonable purchase price of the router without buying something that is overkill for my Internet connection

Many thanks !