It should give good performance because it is clocked pretty high, but it and the Core i3 would trade blows. You can OC the AMD too, making it a nice budget CPU. If you are going to be doing things that will actually take advantage of 4 threads, than go for the AMD, but if you are mostly doing single/dual threaded apps, go for the Intel.
Also, if you get a C3 955, they hit 4Ghz pretty easily. I would get the Phenom II, but still not a 955, I would get a 960t, as it can unlock to a hexa-core and it overclocks well.
Yes, they are basically the same price, but the 955 is clcoked to 3.2Ghz instead of 3.0Ghz, but the 960t has a pretty good change of unlocking to a six-core CPU. They are both BE CPUs too.