Depends how you use it...I got some extra VIP days bc a few people signed up on my page, but when it's up, I won't pay for it. I can count how many DPO I am and I don't really want the 'could I be knocked up' stats, lol.
Yep, all that stuff would just amp up my usual neurotic symptom spotting, I think. As long as you can note stuff on your chart, and as long as ff draws in the crosshairs and pinpoint ovulation etc., I'm thinking that's all you need. But I know some people find the full membership reassuring/useful.