How does the RAF regiment compare with other infantry units?

If i had a choice, i have no experience with military procedures tho, i would choose the RAF. I think that would amazing to be part of the same crew that defended the coast of England in WWII. Marines are , but who do they call on when things go pearshaped? Airforce,thats who. Their the last and best line of defence. Not to mention if u get sick of flying in the army, you can always switch to ariliners! They make loads of money!