The US Mint tried dollar coins with the Susan B. Anthony version, but people complained that they were too close to the size of the quarter, which confused people.
I guess they would lose $.75 on some transactions, but that never happened to me.
The Sacajawea dollars were bigger and gold colored like these, but they didn't really catch on with the public either.
The popularity of the 50 State Quarter Series gave the Mint confidence that by releasing the new dollars with all of the President's faces on them, the public will embrace them and collect them.
Maybe so, but they are barely bigger than a quarter again so John Q. Public-Idiot will get confused and complain, mark my words.