Without a doubt I'd choose race options.
And that's fine
we each play games for different reasons. From what I have been reading in the forums, it seems its pretty split in terms of human only or more races. It will also come down to the characters that appear in the new Mass Effect as well. Say, we have 5 races to pick from at the start of the game, I would say most people pick the race that they relate too. Like if someone is brash and wants to wreck ****, they might choose a krogan. Then down the road, they get a companion who they totally like, or fall in love with(in a videogame kinda of way i mean lol because bioware makes some amazing characters ) and then after some personal quests for that companion, they find that a krogan cannot romance them. Would they restart with a race that can? would it make them think why did they make a krogan in the first place if stuff like that is gated? or continue with the story because in their head, this Krogan is them in videogame form.
Looking back at the DA:I release, they announced romances months before the release and on the forums there was outrage, people wanted to play a certain race with a certain sexual orientation but found out that they cant romance a certain companion. Doesnt that take you out of the universe with those kind of choices? Makes you less hyped about the game? I am super excited for the next mass effect, I want it to be great but at the same time I want to pick the way my character grows throughout the game. In a perfect world, Bioware will have multiple races, with multiple romances and nice little prologues for each race. So people like me, can pick a human (and ignore everything else) and people who want to play as a krogan or quarian can do so as well.
Sorry for the rant and choosing romances as example lol they are pretty important in bioware games. My point is, I want the best game possible for the next mass effect and I feel like focusing on human's only will not only allow that and make it a human story that some people can relate too more but at the same time expand choices, decisions, romances, sexual orientation and have that carry over to the sequels and not worry about techno mumbo jumbo(different animations, diffferent body sizes for armor to model, different voice actors or voice synths to make a human sound like a turian, etc, etc) that would otherwise plague the game and in some instances, bioware may have to cut content from the game since they are unable to get it to work for all races.
Thats my opinion anyways, hope I didnt offend anyone!