A quick look through the books turns up this: Both decks are R/S. The Brain Wave deck allows you to spread a red (for example) deck face down. One card, the freely named card, is face up. When it is turned over, it is seen to have a blue back. The Ultra Mental deck allows you to spread a face-up deck. One card in the deck is face down. When it is turned up, it is seen to be the freely named card. No alternating back colors can be shown. The "Invisible Deck" is a routine popularized by, among others, Don Alan, with the Ultra Mental deck. It is sometimes sold simply as the Invisible Deck.
As to creators: TA Waters names Joe Berg as the inventor of the Ultra Mental deck. Maybe ... My library yields this: Dai Vernon published a description in the October 1938 (issue 49) issue of Jinx titled Brain Wave Deck. In this, he claims to have invented a R/S deck (using magician's wax instead of roughing fluid) in 1930 that is in fact what I have described above as the Ultra Mental deck. (Cards are spread face up, no alternating colors.) In the same piece, Vernon states that Paul Fox showed him a variant in 1932 that is what we now call the Brain Wave deck (face down spread, alternating colors). Later, when material was culled from Jinx for inclusion in Practical Mental Effects, the effect titled Brain Wave Deck is attributed to Dai Vernon, only the red-blue version is described, and there is no mention of Paul Fox. I don't know where Joe Berg enters the picture, but my assumption is that he was first to market the deck (first to call it Ultra Mental?) that is essentially a roughing fluid version of the trick Vernon originally invented in 1930.
I have personally never had any difficulty using a Brain Wave deck ( I spread cards in my hands; doing a ribbon spread on the table would more likely show the paired situation), and you have all seen David Blaine create wonder with an Ultra Mental.
Others have produced interesting variants along the way, notably Ron Wilson and Eugene Burger.