Does more GHZ and more cores = better CPU ?

Not all cpus perform the same at a given clocks speed.

For instance a P4 @ 3ghz gets destroyed by ANY modern cpu at that clock speed.

Clock speeds are only good to compare chips of the same family. so a 3.0ghz P4(assuming the same core, Intel had more than one set of P4 cpus) was faster than a 2.4ghz P4.

Cores in general help with overall experience to a certain point. Software that does not use the extra cores does not get any faster, while programs that do use them will be faster. They still have the advantage when multi tasking since multiple single core programs will work faster at the same time because they will be able to have a core assigned to them by the os.

In general, gaming is still faster on Intel systems despite having less "cores" than AMD(cpu, not gpu) parts. but the AMD parts tend to be cheaper so the cost to performance ratio has to be looked at as well.

I do hope this helps a bit.