b025,
If I am right in interpreting your last post, are you considering using the military to train as a pilot, doing the minimun time and then chasing an airline job?
If so then there are several major things which you need to be aware of.
If you try and join the military as a soldier, they will snap your hand off. But try and join as a prospective pilot about to cost them a sweet couple of million to train and you have another thing coming. Competition to get in is fierce and the slots are reducing all the time. Any sniff that they are dealing with someone with a hidden agenda and less than complete commitment and you would be extrememly lucky to get in. More importantly, once in (from experience) there are many hurdles and hoops to traverse which can really de-motivate and p1ss off even the most ardent trainee. What you fly and when you fly it is really a combination of luck and skill, but there can be little or no choice for the individual in some instances.
Bluntly, if you can stand bu11sh1t, discipline and living the military lifestyle, forget the airlines and investigate joining the military. The 6 years you quote is for the return of service which usually starts once you have gained your wings. For some of the pilots I flew with, this was 4 years after joining, meaning they were not going to leave until after 10 years of service.
Concerning re-training, most military pilots do need to re-train. As ex-aricrew but not pilot, my understanding is as follows. How much depends on what was flown and for how long. The only licence a military pilot automatically qualifies as having on leaving the forces is a PPL. The transport fleet invariably have a big advantage here as their line of work almost parallels the civilian world. A military aviator will without doubt be very skillful within their remit and as such, the transfer from military to civil pilot is normally straightforward even if the nature of the flying is different.
The advantage to be gained by taking the military route before applying to airlines is difficult to quantify because so much can be done in the same timespan. For example you could spend 18 months getting a CPL and Instructors rating. A couple of years working as an instructor before moving onto air taxis and potentially turboprops would provide a distinctly different skills base, and some would say a more relevant skills base. Meanwhile your alter ego is in a desk post 8 years into a military flying career, planning their next posting. Apples and bacon. Both food but can't really be compared.
I'm not sure what advantage is afforded to ex-military types, I don't believe anything personally. However, contacts are everything and this is where the military do win. Usually they know a colleague who has joined airline X and who can help them with good words and inside info etc. These contacts can be difficult to make through the straightforward flying training pipeline.
Obs cop