Hi my dear American friend,
I'm an Iranian English teacher and love my job. Despite the political struggles between the two countries here your accent is quite welcomed by most teenagers. Though this is not the case with me (Got no clue why, but I'm interested in BrE), most of my pupils show a taste for American accent, and in answer to my question for their reasons they say, firstly 'cos it seems to be more free, less formal, shows others you're sophisticated in that Lg,...etc. The other reason is, generally, if you haven't heard anything about accents, you're then more likely to have sort of accent closer to AmE than BrE; I mean the normal way of pronouncing most vocabulary shows up in AmE. Further, my pupils think BrE is a bit fast, hard to use, hard to comprehend......Sorry if my explanation sounds naive! All the best!