NIB offering reduced mortgage to change account

Folks
You might see some pitfalls in this OR maybe there aren't any!

Had a few missed calls over the last week. Turned out it was NIB.

They explained that they are offering a 1/2 percent decrease in the mortgage rate for those customers who have all their banking done with NIB but that it can only be done where 1 of the accounts is a Prestige account;
We currently have a free account, we don't pay for any thing on it, don't need an overdraft facility, write maybe 5 cheques per year.
[broken link removed]

That link allows you to compare the accounts, now the one thing that makes me wonder what the main difference is:
Laser Maestro Debit Card Standard - Its says YES under the account we have now, but NO under this new one.

Any reasons why I should say no to this switch?

Its going to cost us 125 per year for the account but saving %0.45 on the interest payments, the calculation they gave me was it would save us around 300 per year.

But I am wary as hell!

Thanks

Are you on a tracker or SVR at the moment? Will you lose the tracker if you switch?

Can you switch back later on in the mortgage, when the interest proportion of your repayments has reduced to the point that the lower interest rate is no longer saving you money?

As for Laser, it says "Laser Maestro Debit Card Premium: Yes".

MugsGame said:

Are you on a tracker or SVR at the moment? Will you lose the tracker if you switch?

Can you switch back later on in the mortgage, when the interest proportion of your repayments has reduced to the point that the lower interest rate is no longer saving you money?

As for Laser, it says "Laser Maestro Debit Card Premium: Yes".

Click to expand...

I am blind! Sorry I never spotted the Premium!

We are on an offset mortgage, from speaking to them this effects only the interest rate and does not require a move to another mortgage.