There are definitely pluses when it comes to having children who are close in age. They say that if they are less than eighteen months apart, one will never remember a time when the other was not there. This doesn't, however, guarantee a close relationship between the siblings. The plus when they are young is that they always have a playmate. Even with the age difference, they are pretty likely to be interested in similar things and similar shows. If they are the same sex, there is also the plus of re-using the clothing of the first child for the second and having them share a room. Double strollers are amazing! Doesn't leave much storage room for shopping purchases though!
School plays and shows can be a breeze when your children are just a grade apart. You get to see two for the price (and time) of one. However, if it is a classroom event it can be a challenge to be in two classrooms at the same time. It does happen.
Remember to take pictures of each child separately. It sounds obvious but because they are probably together alot but when they are older they might want to see what each of them looked like and have pictures of just them.
When it comes to the school years, it is likely that they will only be a grade apart. That is a plus for a Mom or Dad who choose to drive the children to school because there will ever only be one year where they have to...