Unlike the 4600 and 3800 below them, the 5200 and upwards haven't chucked a meg and a half of cache over the edge in a desperate attempt to lose cost-weight.
This still carries a full 2MB of L2. Unfortunately, neither that nor an extra 200MHz on the clock over the 4600+ makes much difference.
Sure it's a few frames faster in the games and takes a minute less in the multi-tasking test, but not £30-40 worth of boost. It does have a lead over the similarly-priced Intel E6420 out of the box, so there's a certain argument for it if the thought of overclocking still sends icy fingers down your spine.
Really though, AMD's most effective shelter from the Core 2 fallout looks to be the low end, at which a complete non-gaming or media centre system can be built for around £200.