I've lived in Houston,TX for about 10 years and after that I moved to the ME and I've made friends since then. Whenever they heard me say kweshtin they told me my pronunciation was weird. I told them that it's the American pronunciation, but when I googled it I found nothing to back me up. The results showed me that I should pronounce it as kweschin?
I have never heard the pronunciation "kweshtin." The "tion" in "question" is said "chin," or at least that's what I've heard. (Californian here, it may be different where you come from.)