AMD Turion 64 bit vs Amilo 1845?

Hey a bit of dilema.
i had the old 3.06 ghz amilo 1845 (fujitsu) and had to send it back to where i bought after 6 months cause there was a bat problem (it was a defective model i wasnt told about) and after been given a 1.8 centrino which was 2 slow i wanted something same spec as old 1845.
now theres an upgradeed 1845 i think 3.6ghz or 3ghx , 1024 mb ram etc ,128 ati raedon graphics
or
amilo A 1650G AMD Turion ML 32, 64 bit processor, 512 DDR memory . ati mobility raedon xpress 200M

now i know my old p4 amilo 1845 was fast but has anyone had any exp with 64 bit processors and AMD turions,
I use it mainly for grpahic design, multimedia and games like doom 3 . would the AMD be any use for this? or stick with the p4?
Thanks
Karl