I recently subscribed and this is how I feel so far.
There is tons of information available on websites, travel guides, word of mouth, companies, travel agencies etc. If you are the kind of person who doesn't mind digging (and sometimes a lot) and looking at dozens of different places to compile all the information you need, then is orlandoinformer necessary? probably not. But, if you think about how much time it has taken for all your research is it nice to have everything all together and easy to get to, of course. So how much do you value your time vs whatever the subscription fee is.
The things I have enjoyed about it so far is the people on the message boards are great and super helpful. The information is all current and updated (so you don't have to worry about mistakenly reading a 5 year old post). Lastly, OrlandoInformer offers a double money back guarantee. Details can be found on the site prior to signing up.
Overall have I found the site to be instrumental in changing how I plan, book etc my trip? Not really. But I am very well informed, had done tons of research prior to subscribing and have been to Universal and Disney multiple times both on site, as a time share and off site. Would I subscribe again? Probably. It is nice to keep up to date with all the changes as they happen than ask a question on a forum and be told the answer by someone who experience 3, 6, 12 months ago in which time things can change. It also saves you from combing through other sites or if you want to refresh your memory on something it is much easier just to look at one site rather than try to retrace your steps in your research.
If you have never been to universal and are short on time I am sure it would be an absolute asset. If you think the price of the subscription is worth saving yourself research time than go for!