In my experience, I've never seen anything useful delivered in 1-week sprints. That pace generates a lot of activity and a lot of stuff that looks like work, but it's mostly just people planning stuff that can't be done in a week and having meetings about why it can't happen this week and most items being tossed out as blocked.
2-week sprints aren't a whole lot better. I could see maintenance and bug-fixing teams being workable at that pace, but new development projects I've seen have always been a total waste of time on that schedule. Yes, it does keep the business side of the company happy because they see a lot of activity and feel like real work must be happening. But the actual situation is that nothing is really happening--just very loudly and energetically.
My company uses a mix of 2 and 3 week sprints (not on the same teams). My team uses 3 week. I mostly agree with you. Many of our tasks are done well within the 3-week period, but some take more time, and 3 weeks seems to be a happy middle ground. We could probably do 2 week sprints, but our “miss rate” would go up a bit. And at the end of the day, our clients can’t absorb changes that fast anyways.
2-week sprints aren't a whole lot better. I could see maintenance and bug-fixing teams being workable at that pace, but new development projects I've seen have always been a total waste of time on that schedule. Yes, it does keep the business side of the company happy because they see a lot of activity and feel like real work must be happening. But the actual situation is that nothing is really happening--just very loudly and energetically.