As a 20-year-old Uni student who originally decided on DE but got binned from IOT, here's some advice.
University nowadays is not what it's cracked up to be, you will be poor, with a huge overdraft, and worry constantly about where your next tuition fee instalment is going to come from. You won't spend all your time propping up the bar because:
a) You'll be out working to earn your next tuition fee installment
b)You cannot afford the alcohol anyway
c)You'll be working your a*se off with your academic studies because anyone can get into Uni these days, and you have to get a 1st/2:1 for it to have been worthwhile.
All the above don't count if Mummy and Daddy have deep pockets, don't expect uncle Tony to help as the support system is a joke - £3,500 a year to live on is less than unemployment benefit (plus you have to pay it back).
I never regretted choosing the RAF over University and was just unlucky in that I developed a medical problem during IOT. The main reasons students go to Uni is to gain qualifications that will help them get a decent job, you have that opportunity now so take it - you might take a little longer to get Flt Lt but you'll be earning the same as graduates by the time you're 23 (ish) and won't have a £12,000 loan to repay. Plus, you'll really love your job which is something very few people are able to say.
Live for the moment, don't just do the sensible thing. OASC could reject you in 3/4 years time and getting into a UAS is not as easy as it used to be.
In the end it's your choice but I know what I would do..........
Good luck whatever you decide.
Yakkers
PS: Should you go to IOT make friends with the ex-rankers, they'll help you through the tough times and help you appreciate that the real RAF is nothing like what you see inside the wire at Cranwell.
PPS: I'm not all bitter and twisted, honest! Plenty of good stuff has happened to me since I left Cranwell, things always work themselves out.