If you have done on line check in and no bag to drop then yes it's very simple, easy and quick.
You are after the early morning rush of flights from LTN, so security should be pretty fast. Get everything ready, water bottle emptied, zip lock bags done before disembarking, etc, to ease the process and use the bathroom before disembarking.
I'd be twitchy without DoHop. But if it's the morning flight then the aircraft will probably have only flown one earlier sector, so should be less prone to accrued delays. Would Easyjet hold the 2nd flight if yours was a bit late? Don't know.
Do you have your own travel insurance to cover for missed connections, or are able to get it for less than the cost of a new flight?
It's not an ideal scenario, and you have to take your own judgement call. Me, I wouldn't now book new flights on a what's if basis. It would have been better initially to book the insurance, but you didn't.
The thing is that MAN has 3 terminals- you may very well end up switching terminals which is a worse scenario, and it is just a much bigger airport. I see no gain by using MAN.
