Mine are 5.5 years apart. It was our choice, but I wouldn't change it if I had my time again. Time to spend with baby while eldest at school, not dealing with a toddler running off while trying to deal with a baby out and about etc. the eldest was already pretty sensible when ds born. They are 15 and 10 now and I would say get along as well as pretty much any siblings we know. The youngest loves the eldest to play with them and looks up to them. The eldest, while needing their own space, enjoys the excuse to act younger and play without judgment from others because she's 'looking after her brother'.
We haven't found it as hard to do activities with both as you might think, although that presumably partly personality dependent. Eg bigger soft plays, trampoline parks, theme parks etc tend to have more than a 5 year range of ages they suit, both like swimming, both like zoos etc. Some years they have both had Lego for Christmas etc. obviously sometimes we need to 'divide and conquer' but I think we'd want some one to one time whatever ages. And actually, I've noticed less jealousy / complaining to be allowed to do same things as eldest from my youngest than some of his peers, presumably because they've always been at such different stages he doesn't expect to always get to do the sane things.
I suppose one downside is that group socialising as a family is harder as none of their friends have similar gaps, whereas people I know with 2 year gaps seem to have friends where both siblings get a child their age to play with, as the gap is more common. But I suspect we might never have been group socialising people anyway! Also, I had to go 'back' to crawling round a soft play with a baby toddler after having a taste of sitting back with a coffee, whilst my NCT friend watched both of their 2 year gaps kids run off happily to play. But I'd take that over the watching 2 babies / toddlers go off in different directions they'd had to deal with!
As I type they are chatting away happily about a Switch game. They have a great relationship.