The Gujaratis who stay in Gujarat use very pure Gujarati, unpolluted by English or Hindi words. An example my sister gave - "Jo ben tamari seeti boli" evoked laughter among all of us. We were more used to "Jo seeti vaagi"! Another example she gave was - "Aatlu motu vahan nathi dekhaatu?" "Vahan"? We forgot that word long back!
I remember Dinesh growling, many years back, at the chaste Tamil being used by a group of students from Chennai who were going back to Chennai from Hyderabad on the same train as us. One of the students asked him in Tamil if the TT had come and gone. Dinesh spoilt his face after the guy went! Dinesh wasn't used to such pure Tamil!
Another thing that I noticed was people who are away from the state generally have a purer dialect than people in the state. The people in the state acquire the dialect of the region. People away from the state generally speak the 'official dialect', if there is such a thing! Again this is true mostly for people who haven't stayed for long in their native states.
The language of the people of a state who stay in other parts of the country slowly gets mixed with other languages. More importantly, they also get more attached to the culture and traditions of the place than their native states. For example, Sankranthi appeals to me more for the Pongal than the kites!
... http://www.kamaldshah.com/2011/05/differences-in-spoken-language-between.html