I am also from PTP enhanced, in fact just POPed last March.
I must say, BMT really toughens you up, even though the training is still less tough than unit life, as what I am going through now.
When I enlisted on 10 December 2003, I was a zero fighter. My PS, totally unperturped by it, made us do pull ups everyday, to the tune of 2 X 12 before every meal. For someone who couldn't do a single decent pull-up, the first three weeks were hell for me. Even with someone assisting me, I was unable to pull properly. I suffered terribly during circuit training (push-ups, the holding in "down" position especially). The situation got so bad I was using 1 tube of muscle rub a day!
Then on the Monday morning of the forth week, a miracle happened. I struggled past my first pull-up. In fact, I was so happy I treated my close buddies to some iced lemon tea, courtesy of the vending machine at the company line.
Then my weight started dropping drastically. From 76 kg, it fell until 71 kg by the end of BMT. With that, I was able to progressively pull more and more pullups. If you do a search on the archives here, I did once complain about the RT regime my company did. It was essentially a tekan session, but what it did was it enabled me to shoot from 3 pullups to 5.
The bottomline? If you go with all the training faithfully (do not report sick for all the minor problems, etc), you will find yourself improving immensely. For me, I am now pulling 7 pullups (the bike course is really sinful for my stomach!

) In fact, when you get used to it, you will be looking at other things, such as a 6km endurance run, etc... It helps if you get caring instructors who understand the need for your muscles to recover... I was lucky in a way too...