Those of us with kids less than two years apart are considered a certain kind of crazy - as in you'd have to be crazy to do it. I don't know. I think any spacing requires a certain kind of crazy. A big spacing takes the kind of crazy willing to go back to sleepless nights and diapers after getting used to freedom again, for example. And ours will hopefully ease up as the boys get a little older.
It is hard in the beginning with kids so close in age. Two sizes of diapers, two nap schedules, a lot of dependence. But as they are getting older, they are playing together more and aren't so far apart on development levels. They may even potty train together since Wil seems reluctant and Sam wants to do what Wil does. They play with a lot of the same toys now and Wil isn't so far ahead that he resents Sam.
Growing up, there were 3 1/2 years (4 grades) between me and my sister. We didn't have much in common and were at different stages at different times. /there's no guarantee that our boys will be close just because they are close in age, but it's something we can hope will happen. And the crazy is easing up now that Sam is 18 months old.
And a side note: For me, the bigger adjustment was going from 0 to 1 kid (huge life-style change!) than from 1 to 2 kids. I know a lot of people say it's the opposite, but once you have 1, figuring out how to get out of the house with 2 is not as hard. You just do it because you have to. I was much more prepared regarding what I needed to bring with, naptimes, feedings, diaper changes, etc, despite the challenges of corralling 2 while doing all that, the second time around.