P or O
I spent 8 years in the RN and 21 in the RAN as an Observer and had a great time doing very interesting things. These days working with equipment that actually works will make it even more interesting. Whether pilots or observers have a more worthwhile career is a difficult question. I always thought that nights in the hover was very boring for the pilots up front whilst we got on with the job down the back. But it's horses for courses at the end of the day. In any case I always thought that we had a better time than the others who joined the General Service and had to put up with being shouted at, being treated like **** and keeping watches on the bridge before they even started their training.
The bottom line is whether you want to be in the Navy and whether you want to fly are the main issue for you. If the answer to this is yes, then take the offer. If you have your heart set on being a pilot you will need to consider whether to take the risk of being rejected and not having a position in the Navy at all.
Anyway best of luck.