Suppose we are comparing a particular characteristic (that takes comparative -er) of two items, A and B. Compared to B, A displays double that characteristic. There are multiple ways we can express this:
1) A is two times as (adj.) as B.
2) A is twice as (adj.) as B.
3) A is two times (adj.)-er than B.
4) A is twice (adj.)-er than B.
Is this construction valid in any (or all?) varieties of English?