I bought one last month and I got on OK with it. I had one leakage which was quite a severe leakage (well, more overflow really), I guess my periods are heavier than I realised at the beginning, I had only emptied it two hours before. Other than that it was fine, I found it fairly easy to get in and out.
you might even find your flow diminishes, claire, i did. i LOVE seeing what's there, it's not yuck, it's yer womb lining. i always used to when you'd read in mags that you only lost 2tsps blood during a period, but now i see that teh rest is mucus. kinda gross but kinda amazing. if men had periods there weould be an a-level in it.
I've had mine over a year and still find myself childishly amused by the noises it makes on removal. So, yeah, go for it: not only does it makes good economical, environmental and health sense, it is also mildly entertaining.