I did this using the kid prints, since it was a small one. I rather liked the way the block went togther, after I switched the HST blocks out of the corners. I didn't like the choppy way they looked - too much contrast, perhaps? The HST corners may have been effective as a secondary pattern, but I didn't like the way they looked on the solo block.
I think I'll use all the small blue "Kids' Blocks" in one quilt... at least they are no longer orphans, right?