As the kids get older, I find that I am reclaiming some of the weekend back. Previously, it was all hands on deck for pretty much the entire period. Especially Sundays. Now that they are older, though, we do have pockets of free time and bringing them to the park and letting them run around the playground is quite an enjoyable experience.
I do look forward to them being more independent as they get older. I can't remember how I was at their age but at 5, I remember my parents not having to get involved in the day to day. Only with stuff like education and the odd disciplinary problem.
Time flies bit I can't imagine how those with kids with big age gaps do it. To go through the first four years again is really tough. Or maybe it isn't so tough with just one child. I wouldn't know. But with twins... goodness!
Every time I see parents with twins who are younger, I can only empathize with them and what they are going through. But probably the biggest difference is how much additional support - whether it is friends / family or hired help that you can get. Good luck if you don't have any.