My x burkwoodii lasted about 7 years before up and keeling over. That followed a mild winter where for the first ( and subsequently, last) time it stayed evergreen. The very heady fragrance filled the yard and wafted down the block on calm days. They do require impeccable drainage.

tj

Even in my zone 8 they are seldom fully evergreen - "semi-evergreen" is the term they use, but they tend to lose more leaves than they hold on to, even in relatively mild winters :-)

As noted, good drainage is the overriding factor on how well they do or how long they survive. IME, the summer blooming types (x burkwoodii, x transatlantica) are a lot less fussy than Dapne odora or - heaven forbid! - Daphne cneorum.

Ken, yours is looking quite robust. Nice plant!