If the Ironman is your exact size then its a keeper for sure. Great riding bike.
The Prelude should ride great as well but being a little small, even one size, gives it the boot IMO. The Ironman seems to have a great name and will resell for more (possibly) than a Prelude due to the Schwinn moniker. BUT, depending on who sees the add, there are more casual riders who would see the Schwinn name as more desirable, made in USA when they were kids blah blah.

Great finds! The Ironman paint gives it more soul as well.