I have 4 years between my first two. They are boys 6 and 2. It has many benefits and many challenges. Recovery from birth was much smoother, there was less jealousy from the older one etc. Now that the 6 year has school six days a week the 2 year old has plenty of time for individual attention and because he goes to bed earlier the 6 year old gets time with us alone too. The downside is that they really dont have anything in common. They dont play well together. There is a lot of whining and asking if the toddler can play somewhere else. I hope as the toddler gets older and less destructive that will change.
It was enough of a reason for me to have my third closer in age to my second. They are almost exactly two years apart. As hard as it is I think it will be beneficial to be on a more similar schedule.