they prefer smaller more intimate venues than Radio City and Red Rocks.
Very true. But CW played to a sold out house at The Point in February 2006, and it seated 8500 people. (It's closed for redevelopment now, and the seating will be expanded.) But Dubliners are very cosmopolitan, and of course there's a lot of tourists there. Outside Dublin, most Irish venues probably seat fewer than 400 people.