Is there any financial advantage to having an account based in GBP? On a USD account, 1 pip is valued at $10. Is it true that on a GBP account, a pip is worth $15.50 USD?

Seems like that by simply switching to a different base currency(one that is strong relative to yours) you can add %50 extra profit with every trade. Of course you loose in the initial conversion, but it seems like if you are earning $15 a pip versus $10, that's a good thing.

Any perspective on this?

DarkPool 

Is there any financial advantage to having an account based in GBP? Any perspective on this?

Yes, there may be little financial advantage to having GBP account. However we can not expect much. My base currency is EUR.