I just booked two nights at Headley Court in Bunratty which (I believe) is a short drive from Shannon airport. I'm using vouchers on my trip and Kathleen Browne is accepting them as payment. I've not stayed here before, but this B & B is highly recommended by the members of this board and is listed in Michele's book.
You will love Headley Court and Kathleen is a dear. Her kids are my favorite playmates! They are so cute and I get to see them twice a year. I am their unofficial Auntie.
You're right, Headley Court is about 10 - 15 minutes from the airport (depending on route taken).
If you don't have vouchers yet, do not get them! They greatly restrict where you can stay in Ireland. I highly recommend Headley Court: www.headleycourt.net as well as Bunratty Lodge: www.bunrattylodge.com
Our vouchers were part of a travel deal (airline/vouchers/car), otherwise, we wouldn't be using them.
I don't know if this applies to you or not, but.....one thing Kathleen Browne suggested to us was to reserve the night before we got there so we could be assured our room when we arrive in Shannon (plane lands at 7am). That way we can get caught up on our rest right away and begin our wonderful vacation.