The records in MyHeritage include WWII Enlistment and Prisoners of War, Revolutionary War and Confederate Civil War Records and Historical US Army and Air Force Registers, plus many additional collections including Vietnam and Korean war records, army casualties etc.
Obviously, there are a good number of Irish and Irish-American families included in this collection, so this is a great opportunity to seek them out. It's also perhaps a good opportunity for those researchers on this side of the Atlantic who haven't already done so to take a fresh look at MyHeritage. The database is really not very established over here but its collections are growing so it's got to be worth looking in.
I've just had a quick scout around. It claims to hold some four billion historical records and one billion newspaper entries (?). Its headline collections are the US federal censuses since 1790, England and Wales censuses for 1841 to 1901 and a handful of Canadian censuses. It also holds the England & Wales bmd indexes, the US Social Security Index and a good number of bmd indexes for eastern European countries.
Its Irish/Ireland collection is not strong, to be frank. Beyond a few Thom's Directories, some issues of the Belfast Gazette and some fairly ubiquitous texts and indexes, there's nothing here to get overly excited about in terms of records originating from Ireland. That's not very surprising given that so many of Ireland's most important record sets are either online free of charge via the National Archives of Ireland and PRONI or on an exclusive arrangement via RootsIreland.ie.
However, this is a database I'll be returning to (I'll take up the free 7-day trial offer when I next get a free weekend) to seek out extended emigrant family and to check out some of the texts available. What has leaned me towards giving it an indepth 'go' is the interface... it's so clean and straightforward. It's easy to locate the different collections and the search mechanism seems to stick to what you've entered rather than overloading you with stuff that's irrelevant. It makes me feel I'm in charge of my search. And I can't say I've felt that on Ancestry and FindMyPast for some time.
UPDATE: Regarding the 7-day free trial.... it might be worth doing this sooner rather than later because MyHeritage is currently offering an exclusive 35% discount to readers of Irish Roots Magazine who sign up for the annual Premium Plus + Data subscription.