Thanks, Mike. I did an awful lot of heart-searching and delaying; the main 'problem' was the psychological one of spending £3k plus on a bike. I know to many enthusiasts, that's not a fortune, and I'm lucky in that I won enough at Cheltenham races to cover the costs. But even then, even though it was cash I didn't have before Cheltenham, the prospect of spending it on a bike...
It probably goes back to my childhood. We weren't quite poverty-stricken, but I've never forgotten how hard things were for my parents and my siblings (I'm one of 15 children). But I also recall from childhood riding rickety old bikes whose gears never worked properly, so the seed for a trouble-free solution like Rohloff was also planted then, I suppose.
I'll be riding my first 'sportive' (I heard someone calling Sportives Audaxes with a fancy name and 5 times the entry cost!) round Loch Ness in late April with my two sons, which will mean a lot to me. I'll get some good video of the Mercury then (it seems very rare online to find reviews/footage). And I'll write a few reviews and post pictures over the coming weeks and months, in the hope it will help others.
Thanks to all who have contributed to the thread so far - your advice helped.
Joe