On the contrary, I reckon is extremely common across all the main varieties.
Yes. I agree.
However, depending on your where you are, some people might look at you differently if you use the word.
An American once told me not to use it because she thought it is not a word used by "well-educated" people.
Everyone uses this verb every day in Straya and I have no issues with it.
I guess, at the end of the day, if you can get your message across, who cares about what words you use.
My two cents anyway.