Hi Stage -
Of course there are things I miss about working onboard. There are also things I don't miss, just like any job. The camaraderie, the people, the atmosphere is something you won't find anywhere on land. However simple things we take for granted every day you don't always get on ships. You can't just jump in your car and drive to hang out with your friends; if you feel like having a pizza delivered you can't get it, etc...
In terms of the actual job I'd compare it to being a production manager at a road house. You've got a couple rep production shows you run every cruise, the other shows are guest entertainers that will come onboard that day, rehearsal that afternoon, then 2 shows that night, then jump off and fly home the next day. You've got your gear that you need to keep up and running at (close to) 100%. It requires a lot of forecasting and planning for down the road. You need to have a very large spare parts inventory and a rigorous preventative maintenance schedule. If you blow an amp, if a stage lift fails, or if your rigging computer crashes you need to be able to fix it onboard with the parts and the people you've got. But if you have your stage staff blowing out the amps and lighting instruments with compressed air every other week you're a lot less likely to blow an amp because it's overheated, etc... You can't just take your amp down the street to have it fixed. It's very fast-paced and everything is accelerated.
If you feel you must be part of the creative process and build a show from scratch then ship life is not for you. There is a bit of that, but you're not with the show from conception to closing. You sign on for your contract, keep things going, then sign off, and things will keep going long after you leave.
Personally I think it's great fun, a great way to see the world and put some money in the bank. In my opinion it's all the best things about touring with none of the downsides, because your entire theatre, cabin, and staff tours with you.