I’ve got an RX comp I’ve been running as a demo bike for a few months now. To be fair, I’ve not ridden it all that much, but the miles I have done it have been very enjoyable. £1200 may not look all that competitive on paper, but it does come with BB7’s (rather than BB5’s which CX bikes are often downgraded to) and no obvious corners cut on the spec.
If you’re after a 55cm bike, I will be selling mine on very soon, to make way for another demo bike. It’s probably covered no more than 150 miles if I’m honest, as I’m usually out on either one of my mountain bikes or my road bike. My email is in my profile if you are interested.