Ah I see Lady - well that is exactly why I went for it too. Because it said it could predict up to 6 days ahead. And I hated the whole temping in the morning thing - gah!
It certainly was easier to wear the sensor all the time to get the temps, so it was easy to use.
But like you I read all the guff and thought 'wow - it can predict - it must be magic!' I actually thought (and am maybe embarrassed to admit) that maybe it did more than just take temps (by magic perhaps)? I thought it must do more to be able to predict it in advance. I thought maybe it did more and they didn't explain all that in the literature because it would give away their secret sort of thing?
However, what I think happens is that it uses the data it builds up and then just tells you 6 days before you usually ovulate. Now, I had a 28-29 day cycle so the first cycle we used it it obviously predicted I would ovulate on day 14. But it never seemed to change it's estimate based on the data it was recording. However, we conceived on the 3rd month of using it so perhaps it didn't have long enough? (giving it the benefit of the doubt here).
Also, DH liked the money back guarantee thing, which said that if you'd had sex at least once or twice (can't remember which, twice I think) during the 'green' days and nowt had happened in 12 months you could have your money back. But then when it had worked out when I'd ovulated, it retrospectively moved my 'green' days to be around the actual time of ovulation rather than the predicted time. My ov's were not masses away from day 14, but still varied every month. So maybe a week after ovulation, when it 'confirmed' ovulation, it would move the green days (which did at least show if we'd hit the most fertile days) but I worried about then whether we had ticked the box for the money back guarantee. For the 3 months that we used it, luckily we did even on the revised fertile windows but I always worried that if we aimed for the predicted ov window and then it was off, we might have not hit the right days (either for the best chance or for the money back thing). It was sort of as if there is no use predicting the ov date if it could be 3 or 4 (or more) days before I actually ov because if I aim for then, then I'd miss my real fertile window.
And the other thing, when I had the 'moving ovulation' in the last cycle (which I wonder if it was actually ov and then an implantation dip?) and I emailed them about it, they said 'well, we recommend that you SWI every other day just to be sure'
Well, Jesus, tell me something I don't know - I thought it was going to predict it for me so I could be more targeted (in no way was I fed up of having to SWI every other sodding day) but to then go and say well really you should just do it every other day - I was a bit 

Sorry, that;s a bit rambly - hope you can make some sense of it.....