For me and my spouse, it is totally worth it, if we're not staying in the haven. We've had it on our last 2 cruises - a 5 day Carribean trip, and a 10 day Panama Canal trip. We are taking a very port intensive cruise this summer - just one sea day out of 8 - but if we hadn't booked haven, we'd definitely get the vibe.
We enjoy being outside, and really enjoyed being able to always have a comfortable chair without feeling like a packed sardine, and also enjoyed it being on the quieter side. It wasn't quiet - boring, but more chill. We became friendly with many of the other folks up there, and enjoyed the bartenders knowing us and our names (and drinks!). Most mornings they had coffee up there, so that's where we'd run up for a nice cup outside to take in the sun and the sights.
For us, if we had two full sea days, not having the vibe (or haven) would be a deal breaker, because we find it so relaxing and enjoyable.
