my girlfriend and I did it a few years ago...went the first week of June, and got SUPER lucky with having a week of good weather. EXCPECT RAIN!!!!.
We went North to South, and enjoyed it. The Most southern part is by far the hardest...lots of mud, logs, roots, rocks, etc. Took us an hour per KM. The northern part is more just flat hiking.
I would consider myself novice (and overweight) and can honestly say it was one of the hardest things I have done....But damn rewarding. 3 years later, I think I am ready to tackle it again...in another 2-3 years
We had proper equipment that made it so much better. Spent about $1K on a new, lightweight tent, sleeping bags, proper food makers, etc, and it helped out enormously. Do whatever you can to minimize your backpack weight.
Two musts: Gaitors and Poles. I broke a pole on day 3, and it made the last few days a bit harder. I read prior to going that poles make it 15% easier on your body.
Gaitors keep your feet dry, which is super important when you are hiking 75km.
Let me know if you have any more questions.