Local has huge advantages - local friends, walking to school, etc. Even more so at middle school, when they can take themselves if school is local - obviously less relevant now, but if they go to first school somewhere else they may want to move on to middle school with their friends.
So for me, there would have to be strong reasons not to go local.
However there are other non-educational factors which might make a difference - in particular, if you need (or might need in the future) wrap-around care, you might want to choose a school that has a breakfast/after-school club. You might also want to check if the middle schools prioritise children from certain first schools.
As Hulahoops says, you need to look at the admissions information to find out your chances of getting into different schools. Each school has criteria for determining who gets the places if too many people apply. They vary, but priority may be given to those with siblings there, those living in a particular area, or those with church connections (for a church school). Within each category, it is then usually done on distance from the school. You can find out which priority group they got to last year, and then how far away they got: it might be that they got to the "everyone else" category but only got 2 miles away from the school on that.
If the school is usually under-subscribed, you should be able to get a place, although be wary if, for instance, there's a big new housing estate - that tends to mean a lot more 4 year olds, as people often move as their families grow. You get more than one preference, though, so using up one choice on a school that might not have a space isn't necessarily a problem.
Needless to say, the schools with the best reputation tend not to be under-subscribed, although this can vary, particularly in rural areas where most people are likely to choose the nearest school.