I grow the cultivar Exchorda 'The Bride'. It's a very nice shrub and pretty easy to grow. The only complaint that I've had is that it hates wet summers (the last two have been murder on it). The foliage melts and drops off and the whole shrub can look pretty ratty at this time. When things dry out again, the foliage resprouts.

i see it occasionally in my area; most often it's used as a loose, open hedge or screen, much like wax myrtle might be.
the neighbor up the street has a couple of big, floppy ones.
there is a cultivar that is a hybrid of two species, exorchorda x macrantha 'the bride', that is more compact and dense. i know i have seen it online somewhere.
might try a nursery like forestfarm.com for this one.

Thanks everyone!

Jenn