I believe that BA SH at LHR and EZY LGW are probably similar levels of flying hours. BA at LHR is probably more time in uniform than EZY from the regions.
The major factor for me that has improved my lifestyle by a factor of 10+ is the ability to control when you work. Even from the first day you walk through the door you stand a chance of getting triplines that give you the day(s) off you're after and the type of work you prefer. I quite like early there and backs, weekends off but mixed in with a few nightstops a month and that's broadly what I get. Everyone wants something different and that's what makes bidding for work so helpful. Even if you're not 100% satisfied at publication then eMaestro or iBid etc helps you to tweak it to get more of what you want.
Knowing you're going to be working next year on your friends wedding in August on a 5/3/5/4 was painfully frustrating because you knew that every annual leave day would be red. As I said before though, everyone wants something different so I'm sure that a fixed roster works perfectly for some people.
I found the flying in EZY pretty dull and the ability to see some of Europe's best cities as well as the odd day off on the beach after a bit of mid haul to be a welcome change.
Each to their own but I'd be wary of choosing one job over another simply by comparing block / duty times. I'd much rather fly 900hrs a year on the days I would prefer to work rather than 700 over days I need to be off. You don't need to be in any time at all to start getting control over your life and with rumours of large recruitment this year and next mean that you'll enjoy that control very quickly.