I've had mine for over 12 years now and I do love them. With a suitable amplifier, they can indeed do some decent dynamics, but they are not of course near the top league for this even when well partnered.
I have been wondering myself if the next step could be the Graham Audio ls5/9 - it's apparently more lively and punchy than the C7 but still keeps to the BBC family sound in the midrange. However there is a problem - sales to Finland happen from Denmark and the only retailer for the Danish company does not actually carry any Graham Audio products, so while I can probably order one domestically, I can't get a demo without travelling abroad..