Personally, I don't care for the MC gender, but I COULD care for the design the MC has.
Both you show work well for me, so the real question would be "which gender works better for the character? If there is one that works better"
You can talk some topics "better" with a female MC than with a male one and vice-versa.
E.g.:
If your story takes elements of let's say, México, women here tend to be disregarded more often than men on stuff like sports, taking the lead, science, and such. Assuming the MC is a female and wants to be involved in action and so, then it can had to her personality that she's going against what people on her society say.
Or perhaps is the opposite, and a male MC would be in a position he never wanted, but was forced to be in because he's male. Then it could deal with things like taking responsibility on things that are needed but one doesn't really like to do, and even wonder which masculine traits are actually masculine, and others just egoist or self-destructive.
Maybe it's none of the latter, or a mix of them both, with some differences, or the society the story takes place in has different ideas.
Really depends on the message you want to deliver and what you feel comfortable with.
If there is still doubt, I'd say go for the gender you first imagined your MC with.
I too have gender swapped some characters of mine and some did work, others I really didn't feel comfortable with because of how long I've imagined them as the other sex.
Do what works for you and your story.