personal loan, why would you choose say 6.1% APR over 3.9%

[p1tse]

My thinking is based on the following, taking HSBC as an example.

Anything between £7k-15k it is at 3.9%

Anything below £7k is 6.1%

If those who gets through the checks and are legible, why would they go say £6k?

Would it not be better to go for the £7k to get the lower rate and use say the difference of £1k as over payment