I am working as crew for Emirates at the moment and I am planning to do my Pilots ATPL.
The plus side is that if you work for an airline like Emirates where you tend to have a lot of time off then you can do your training around your work commitments.... however if like me you are trying to secure a Cadetship with a UK airline then it can be difficult to attend interviews.
I suppose it is always better just to go for it and make the financial commitment which i plan to do should i not ( and to be honest its most unlikely) secure a sponsorship.
I suppose on the other hand that a year or two working with pax gives you a better understanding of CRM and might look attractive to a future employer????
Any airline experience is an advantage in a highly compettetive industry !!!!!