When ya move from yer birthplace, how important d'ya think it is to imilate with yer new area accent-wise?

D'ya think it's summin' that absolutely EVERYONE should do, (WITHOUT exception), or d'ya think should be a matter of choice? Only, I moved up from London to Lincoln, (England), WELL over two years ago now, and I still have a VERY broad London accent, (and for the record, that's actually by choice, as I DON'T wanna lose me identity as a Londoner!) However, me sister, (who's now lost her London accent completely), tells me that my point-blank refusal to make meself sound like the locals in our new city makes me sound, AT BEST, TOTALLY out of place up here, and, AT WORST, actually quite bloody rude and arrogant! What do you guys think on this matter, please? (Especially those of ya who've NEVER answered one of MY questions before!) I'd REALLY appreciate YOUR angles on this one, please, guys! Much obliged in advance! Peace and love! Be lucky! :)