Gemini i have never used but it seems like that they are charging 0.25% per trade. If you're going for convenience then i suggest you stick with coinbase because they are by far the best exchange on the basis of convenience only.
If you're an active trader executing thousands of trades per week then probably look into btc-e, even though they aren't regulated and quite shady they are fast, the spreads are low, and the fees schedule is low as well.
But it does seem like that you're promoting Gemini here...
Guys, as you can see I just registered the forum and this is my probably 4th or 5th posts here. Who the hell am I to promote Gemini? Why would people believe someone with freaking 3-4 posts on this forum?
I just transfered my money to Gdax by the way. After one trade, I would like to calculate all the fees for trading and withdrawal to my bank account.
Thanks a lot guys.