It's kind of a nice, gentle old fashioned movie. I thought Gary Burghoff did a reasonable borough, although it probably wouldn't fool anyone from Galway or Cork. However, it isn't any broader than those in The Quiet Man and some of those actors really were Irish. I could have done without the fake, bushy eyebrows though, but they probably did that so he'd look his age or older (I think he was mid 50s or so at the time) and so people wouldn't say Hey, Radar O'Reilly's playing a Leprechaun. And it was faith based but not advancing one religion over another. My other recommendation is if The Irish Rovers ever need a new member, Gary Burghoff, even though his background isn't necessarily Irish, would make a good one.
Review of Behind the Waterfall
