Haven't looked at that product. I did download an evaluation copy of the software made for HP by Serif.com called PosterDesigner Pro. They want something like $595 US for it (ouch).
Then I discovered that PosterDesigner Pro is merely a subset of another program made by the same software company called Page Plus.
I got Page Plus X3 for $49. It's now version X4, and if you call the 1-800 number and order the CD and book by mail, you can get it for nearly half of the download-online price of $99.
It makes it easy to print posters.
How HP can justify taking a subset of a program and sell it for $595, I don't know, because that is insane. Page Plus does a whole lot more than just posters.
I guess that's the beauty of what they'd like you to believe is value-adding. And they didn't do a darn thing to it to add value except slap their name on it, and offer a few more pre-made templates.
They had Serif change the file type of the templates though, so if you try to use what you made in the trial version of PosterDesigner Pro, with the Page Plus - well - it won't work. Everything looks the same, but the file extension is one letter different. Even if you try to rename it - it just won't work. Smart cookies those HP marketing geniuses, I guess.