Talking from Italy:
DO NOT USE THOSE SERVICES! Unless you are in absolute need of quick cash and can't find a better alternative.
I worked for one for a year and it was literally a legal scam.
The rates will be either incredibly bad (because of "no commission") or unbelievably good (because there's a very tiny text saying they'll charge a 20% commission plus a fixed fee.
In italy, shops are forced by law to accept cards, that will surely give you a better exchange rate.
If you absolutely need cash but are not in a hurry, go to a post office. They will give you one of the best rates and charge a very small fee. But they take a day or two to get the money.
If you need it quick, the ATM's that you'll find everywhere will give you a decent rate. Not as good as the post office but certainly better than those exchange windows.