So what you are choosing now is the front-end library/framework. There is no perfect solution. Only a good fit with what you are trying to build.
Angular gives you a framework (that is why it is so big), so you have everything you could ever need for the front-end (at least in theory).
Blaze, React and Vue just focus on displaying stuff and doing that very good, so you then need to import other packages to get everything running, but at least it is only what you need.
I haven’t worked with Mithril, I took a quick look on it and it strikes me to be like React without JSX (you also have the option to add in JSX to Mithril if you want to). So strip down version of React would obviously be smaller and faster than React if that is what you are looking for.
One other thing that you have to consider is integration with Meteor. Since Meteor is also a build tool that becomes quiet important and then also is the integration with things like pub/sub which things like React and Angular have already figured out. With Mihtril you have to do that yourself. So that is where the recommendation to use package like React comes from.