Hi Bloggsy II,
I'm by no means a fan of TRSS, though having regularly flown with it's graduates, it's mostly a means of getting the same calibre of guys as they would anyway, whilst avoiding having to pay for their TR. They do it because they can. As employment picks up EZY will, as they have in the past, shift the emphisis back towards full time employment.
The difference is EZY will use TRSS to save money as long as they can get enough suitable guys to go that route, and then have them operate under EZYs high standardof flight OPS and conservative SOPs. FR will take whoever they can get and have them operate hell-for-leather. Any airline might have a mis-hap, but I would certainly put the odds of it being FR way ahead of EZY.
As to the whole fuelconservation thing, well, they consider the avoidence of fast approaches and go-arounds is worth the extra gas and, after all, it's their train set!