I know that some of their pilots do get FO's jobs, although no idea what proportion of the total or of the pool. If you are dead set on big jets and nothing else then this or similar is arguably a good choice. However it isn't going to help you towards any other type of job - if they find out you've done it any turbo-prop or GA operator will assume you will be straight off to the low costs or charter operators as soon as you have the hours for a look in. Many don't like that for some reason!