With the benefit of hindsight I would go commercial. I do not regret my 12 years in the Fleet Air Arm but that's all over now. I am now in the situation where I am 40 years old with 5 years of commercial flying behind me and as an FO am on exactly equal terms with a young chap/ess of say 25 who has done the basic course and minimum hours at, say, Ryanair or easy and is already up for command.
When I joined the Navy, the airlines were not recruiting that much and most of my peers were mad keen on joining the RAF or Navy. I see Flying now as a Lifestyle/pay equation rather than just an exciting job. Much of the prestige of being a pilot has gone and so has a lot of the fun. Possibly it's just myself facing up to realities but if I had started flying commercially in my early 20s, I would be very wealthy by now and would have run more of my life on my own terms. Also, when I was a nipper there weren't that many opportunities to borrow 35-40K for what, as I remember, most folk saw as a 'pie in the sky' dream. Hope this helps.