If you're happy to be a S/O for a long, long time then go QF, if you want more personal happiness than monetary gain then JQ is an option.
I don't believe that up to five years as a S/O qualifies as a "long, long time".
I'd also say that a statement about JQ providing more 'personal happiness than monetary gain' is a highly subjective thing and requires the additional statement that normally follows financial adds on TV......the one that is something like 'generic advice only; individual circumstances vary and proper advice is required'. Your advice is a long way from 'proper'.
It depends on how you view your time as a S/O and what you see as the ultimate prize. Personally I've got no problems holding out in QF as a F/O for the next 1-3 years for a command. Even if it was seven to ten years I'd still stick it out with the prospect of a mainline command at the end of that. Along the way I've still enjoyed my job (personal happiness) and I've still got more money in the bank than a JQ captain.
All our pilots in JQ are good people, we have great CRM and we're a friendly bunch.
Talk about rose coloured glasses. Can you imagine the response from a JQ driver if a QF driver tried spinning a line like that. The version from this particular QF driver is 'We're mostly good guys and gals, most of our crews are great at CRM and we're mostly a friendly bunch'. To state anything other than that is deluding yourself! i know there are loons in JQ the same way that I know there are loons in QF....I read their posts on PPRUNE!
I believe that if the pilot shortage holds up then QF will have no choice but to progress the Group Opportunity list and allow these types of transfers. They're not going to get qualified drivers for both groups any other way!