EuroLGW is definitely NOT the same contract as the other fleets. The allowance structure and agreements are completely different and pretty much everyone at LGW EF is trying to transfer to LHR.
Allowances at LGW are much lower than at LHR and the roster involves a lot more long days and doubles. However, EF LGW is a fun fleet and appears to be more laid back than LHR.
Personnally though, for financial reasons I'd go for LHR.