no, in memery increased by 25% too, if I remember correctly.
it will be roughly the same. Since data and commands are seperated in L1 at least data will not suffer.
Also, while you don't have L3 with Athlon II you will get a bigger L2 (except if you are coming from an old X2 6000). 1mb/core is not too bad. More than most old X2s. And the Athlon II Regor core is faster on the same clock than the old Kuma or Windsor/Brisbane. So.. don't worry too much.