I'm curious about others' experience with Purple Passion rhododendron. This variety has been pretty heavily promoted and touted as hardy to -20. It does have good purple flowers, but I've found it to be a variety that suffers greatly in the winter, even an exceptionally mild one(for Maine) like 2009-2010. It's not killed outright, but there's lots of branch dieback. Right now, my 2 Purple Passions, both of which are sited in protected areas look worse than any other varieties. How does it do for you?