ateres- nice kids, hashkafa is very mainstream, bais yaakov but individual. they have tracked classes so it can be very easy or average. it depends on your grades. but they work with you. and tehre is a normal amount of free time.
meohr– their hashkafa is each person goes in the mehalech that is best suited for them because they are each their own person with their own strength and weaknesses. its about doing whatever it takes to become close to hashem in their own way. and there is NOT ALOT of free time. classes all day. 3 hours a day to do schoolwork which they have alot of. i dont know that much about the girls.
darchei bina- much more open and different girlwise, average free time. the classes are chosen so you pick when you have your own classes so you sort of make your own schedule. so you can make it that you have the free time when you want it. hashkafa is pretty much the same as meohr but more open to different types and different backgrounds.
maybe look at other threads about seminary. Other threads have information on these 3 places. There is no reason to keep opening new threads over and over again especially when these places have been discussed in other threads.