I toyed with the idea of planting one here for a long time since it
would almost certainly be hardy enough in my part of the world. The
problem is that Corymbia (the new 'old' name for this and a fair
tranche of allied species) ficifolia does not always come true from
seed and the resultant flower colour can be variable. With a 5 - 7
year or more wait and a fair amount of space taken up in the process,
the flowers could just a easily turn out to be pale cream (usually
through hybridisation) or pink as they could the more desirable rich,
deep red or orange scarlet.

The answer might be to find a grafted plant with the scion taken from
a proven colour variant, but I suspect finding hen's teeth might be
easier in the UK. Growing several in large containers is a possible
alternative since they can be persuaded to flower in this way.
However, if I wanted to plant a good one out subsequently, there's a
danger that the root system might never develop properly after
planting with the risk of the tree coming down in a storm.