I just installed a new kitchen sink pull-out type faucet with shower spray. The pressure seems rather low compared to other faucets in our house (pressure is not the problem). At work we have a pull-out faucet with the same 2.2 gpm flow rate and it has good pressure. I installed our faucet using the quick-connect braided hoses. I'm wondering how much, if at all, these quick-connect type hoses (and the length used) can affect the volume and/or pressure from your faucet--the faucet at work has copper supply tubing, by the way.
Also check your flexy's to make sure their not kinked. There may also be a water saver , where the handle attached to the hose. You can try to remove it, but the rubber washer has to stay to make the seal. I know what you mean @ the low flow rate, i have installed the Moens, and from spray to stream is not much. Check the gpm on the aerator, you may be able to buy a dual thread aerator with a higher gpm.
I think what you have is "gourmet-faucet" the type that you can grab the spout and extend the hose and use as a spray....These faucets are notorious for low volume...even worse when they were first introduced in the u.s. from europe 12-15 years ago. I find the biggest mistake is at installation time when the installer does not flush the water lines before making connections. erik