Page 1 of Philips 28 inch 6515 - Couple of questions

I`m thinking of ` upgrading ` from my Hitachi C28W511TN to the Philips 28PW6515. A mate wants the Hitachi at my knock down offer price !
Couple of things.
1/ Most importantly - how do I ensure the one I get doesn`t suffer from the ` artifact ` picture problem I`ve seen mention of ? Is there a serial number or something I should look for ?. Given that I`ll be buying it off the net I would be really quite severely hacked off if I had to return it. Apart from anything else how would I know the next one wouldn`t suffer from it ?
2/ Where`s the cheapest place I can get it from ? Empire direct are cheaper than QED at £ 549.98 but that`s the only 2 websites I know of.
Cheers for any info. Dead excited about getting one but I`m being put off by the artifact thing...

www.unbeatable.co.uk £555ish + £27 delivery
www.hispek.com £550ish free delivery
Currys / Dixons etc £628 in store

This set was my fav but too many people having too many geometry & artefacts issues, not worth the hastle - look elsewhere

JVC got some new sets out this week + Check Panasonic 28PL1