In general I would say Jet2 are a good company to work for.
The best gig there at the moment is a line Captain on the B757.
work/life balance differs dependant on fleet/base/rank/‘extra qualifications’ and luck.
TRE pay is approximately 22% on top of standard line Captain pay (unless you’re on the much higher old pay scale of course!).
TRE workload is, subjectively at least, more than a 22% increase. Also, it’s worth bearing in mind that certain winter deals are not available to TREs(or TRIs I think). These deals can be very lucrative in terms of extra time vs loss of pay.
do not expect many, if any, SBY or reserves as a trainer in general and definitely not as a sim trainer.
management are generally hands-off and leave you to get on with things. Of course this can be good and bad! Pragmatism is an often used word but in reality is only acceptable if it’s the same pragmatic view the managers would have taken anyway.
trainers in general got a raw deal during Covid, sim trainers even more so. That may be in the past now but the goodwill lost has not recovered yet.
if you enjoy training and don’t mind a full roster while watching your line colleagues enjoy a very easy winter then go for it. The trainers are generally a really good bunch with a wide variety of experience and backgrounds.
are certain groups favoured? In general, yes. If you have a military background you can expect to progress further if that’s what you want. If you’re not, it’s still possible to progress of course but it certainly seems to require a lot more networking and brown nosing.
I hope this honest appraisal helps you, or anyone else, in making your decision.