Is it not pertinent to address the fact that some airlines don't actually accept pilots from a modular background? Ok, they may be few and far between, but if someone is wanting to aspire to be employed by BA at some point, they aren't going to be if they've pursued training via the modular route.
Everybody's circumstances are different, and indeed change over time. It's not always so clear cut as to which route will suit each person, which is why doing your homework is very important.
I'll echo what people are saying about education. It is very impotant to achieve the best results, even in subjects not 'relating to' flying. Not only will you be a broader, more well rounded individual, but you'll have more options with regards to employment. Getting a degree isn't a must. I did well in my A-levels but have been fortunate enough to secure a training place early in my life without wasting time doing a degree in something I have no interest in. If you think it is sensible, and there is a subject you would like to study in more depth at university, then by all means pusure a degree first, but don't do it by default. Do what's right for you.