Already exhausted 3 rolls and the results so far have been mixed. My first roll was an expensive disappointment (as I suppose you'd expect) though I shouldn't have ordered the medium-sized prints and one-hour processing - now getting the smaller + 24-hour option (About £4 less)!

I'm discovering that a basic theory on f-stops and shutter speeds doesn't necessarily mean you know how to apply it!
Also, I've been taking notes on every photo as well as what I should've done to correct it. So:

My first roll was largely underexposed. (4a.m. during a powercut..)
Second roll was over.
The third was half under, half over(!)

Though in each roll there were at least a couple of successful, well-exposed shots.

I'll throw up some of the results in a while. About to develop the fourth roll and hoping for the best!

All the best!
Gyro