Yes, I purchased a copy in the US. I don't have it here with me at the moment. It's available from Family Roots Publishing and at Amazon from other suppliers for about $20.
It's certainly a competent work, and well-written by a librarian with a good knowledge of Co. Westmeath. It's also part of a series from a good publisher and editor, and not just desktop publishing or personal pet project. And finally, it's the only book I know of that focuses on Westmeath.
I still found myself disappointed, maybe because I expected more. It seemed to me mainly a catalog of sources, and those sources were only available in Ireland, either in Westmeath or in Dublin. It would be invaluable for planning a trip or commissioning research. If you're stuck on this side of the pond it's less useful.
Again, I'm not looking at the book as I write this, and am not competent to compare it to Grenham's work. You should have a look at it and form your own opinion.