Camcorder advice - Panasonic NV-GS300 or NV-GS320?

I'm about to purchase my first camcorder and have narrowed it down to one of two - either the Panasonic NV-GS300 or the Panasonic NV-GS320.

I read about GS300 a few months ago and was about to go ahead with it, however I have recently heard about the GS320 which for some reason is only £15 - £20 more than the GS300.

I can't see any major difference in specs, and both are 'Best Buys' on the Which website. But on the Which website the GS300 has been reviewed at a price of £600 even though I have seen it for around £325, while the GS320 has been reviewed at a price of around £360 which I have seen for £340.

Why is price difference on Which so huge in comparison to the actual prices I have seen on purelygadgets.co.uk?

And more to the point - what is the difference between the two camcorders given that the actual price difference is negligible?

Shouldn't the GS320 be better than the GS300??

Any advice much appreciated as usual!