Some time ago I had a good look at Nik HDR Efex and have made use of it for several large prints, particularly B&W night scenes with sharply lit parts of buildings.
I've just written up a review of some aspects of the newest version HDR Efex Pro 2, which as well as being faster and easier to find your way around, seems to have reigned in some of the more egregious (to me ;-) ) excesses of many HDR creation programs, with many of the default and preset settings looking decidedly more natural (my world lack halos around buildings ;-) )
http://www.northlight-images.co.uk/reviews/plugins/hdr-efex-pro2.htmlHope it's of some interest, particularly for people who might share my preferences for images that don't wildly assault the eyes :-) :-)