Being sophisticated will create a different persona, which is not you!
If you refer to the generic television "non-regional accent", it exists in the wild only in Iowa and west-central Illinois.
These poor people speak English exactly how it is phonetically constructed.
Unlike everyone else who speaks English in the world, for whom proper phonemes are few and far between.
The servant often is resentful of its master. Britain is a mere satellite state belonging to the US. We wave the bone and you salivate and wag your tail.
When Orwell wrote of Britain as being "Airstrip One", he wasn't just pointing out its only importance in the second World War, but also its only useful role in the world going forward; as put into inevitability by Churchill.
To which an American would respond "You and what colony?". The chances of Britain retaking the USA are... well let's say that the Red Socks have more chance of winning the world series two times in a row than that happening.