To buy or not to buy?

Iknownothing
Iknownothing Posts: 5
edited March 2014 in Road buying advice
Hi, new on here - you'll probably be able to tell!
Currently got a 2013 Giant Defy1 but kind of want an entry level Carbon bike and like the look of and what you get on the Planet X pro carbon for £1000. But is it really worth it over the Giant which I believe is one of the better non-carbon bikes, which is why I got it originally? I realise RRP of the Giant is not far off the same as the PX, but then I didn't pay full price. And thanks to Cyclescheme, I would be paying much less than full price on the PX as well. But that restricts me to £1000 mark. So, stick with what I have or go for the PX (and sell the Giant)? Or any others to consider about that price? If it helps, do normal stuff but did a duathlon yesterday and fancy doing that again so might be a bit of a mix.
Thanks for any comments!