Re Powerpoint decks, it's probably safe to assume you wouldn't be burning the midnight oil as much in the public sector however there will still be many, many occasions where your work will be flicked through in 5 minutes and discarded :)
Technology in the public sector is a very mixed bag. You could get to work on some really interesting projects or programmes depending on what sector you go into (huge change going on in the Transport and Justice sectors at the moment for example). The downside of this is if you are not careful you could go somewhere where you are essentially a contract manager, whereas at your level I would be advocating getting as much hands-on technology experience as possible to rule out what you don't like and find out what you do.
If you do indeed consider the public sector and are thinking 'big picture' and longer-term, get as much formal training under your belt before you make the jump. The vast majority of public sector depts will have a minimal/non-existent allocation, so if you can get qualifications relevant to your chosen discipline prior to moving (Prince2, ITIL, TOGAF, BCS Business Analysis, Agile, etc) then all the better.
My gut instinct is to advise you to get a better handle on what makes you tick and try to get a promotion or two under your belt. Worst case scenario at the moment is you make the jump into a relatively junior role, realize it's not something you enjoy but have little prospect of promotion or getting back out and become stuck in situ counting down the days to your (admittedly great) pension.
Unfortunately having only worked in the public sector and consultancy (FS), I can't really give an opinion on other private sector industries, but hopefully someone else on the boards will be able to share their experiences with you.