My boys are 15 months apart. My oldest is almost 27 months and my younger one will be 1 in less than 2 weeks.
I love that they are already forming a deep friendship. They love playing together. Watching them make each other giggle is one of the sweetest parts of motherhood for me. But I am a stay at home, SAHM. We currently only have 1 car which DH takes to work, so most of our time is spent at home. My boys are also really good sleepers, both STTN without any help from us, and both take at least 1 good nap in the middle of the day. This makes a huge difference because it gives me a couple of hours to get stuff done while they sleep. We also plan to home educate, so no concerns about teacher perceptions. When DS2 was newborn it was tough, as DS1 was always trying to poke him in the eyes, so we really could not leave DS2 on anything within rear of DS1, so floor time was rare. It took a few months to train DS1 out of doing that kind of thing. We love our family dynamic so much that we are already trying for another baby.
My older brother and I were 18 months apart, and went to public school (in Scotland) and never really had any issues because of our age gap. We were best friends growing up right through until high school. As adults we are not as close, but we do live in different continents, so no big surprise there. We do know that if we ever need the other one we will be there for them. My younger sister and I have a 6 year 4 month age gap (so almost 8 years for my brother & sister) and she struggled with insecurity her whole childhood, as she was never as close to either of us as my brother and I were to each other. Even my mum has said it felt like raising 2 different families.
My DH and his brother are 21 months apart, and still very close to each other. (BIL took the day off work to help support us when DS1's labor was transferred from home birth to hospital, and was the first in the family to hold DS1 (except DH & I.)
ETA: I have had low grade anemia for over 10 years, and it was NOT any greater an issue than normal during my pregnancy with DS2.