Jvalera
Newly Enlightened
Finally got one ...Awesome
I was comparing the same pictures yesterday and it is true that the length of the threads on the XT11 and XT30 tubes looks identical (unlike the one on the XT20 tube). The battery tube of the XT30 looks thicker though so it still might not fit into the head of the XT11 - and the other way around either.
I've ordered both lights yesterday so I should be able to confirm it sometime next week.