Pedals vs. Processors

I am looking to buy some different effects here soon. Have bought a couple pedals before but was wondering if I would be better off buying an effects processor instead. A friend of mine at the guitar store here in town says that you can tweak the pedal more than you can with a preocessor. Before I go out and slap the money down I was curious as to what you all think about both and if you could give me some insight. And by chance if you prefer processors over pedals what is a good brand and model to consider.