In reply to tasmat:
The bag may not last as long but I am still sure it will last a long time if cared for.
Rab made me a bag 20 years ago (550g fill, extra long, no zip, total weight 950g, good for -6 deg C and I sleep cold)
If you compare specs of modern bags my bag is lightweight for its performance and it is still doing very well. I expect at least another 10 years from it.
PHD appear to be the leaders in down equipment and if I was buying another I would go to see them. Though some of their temperature claims seem a bit optimistic.
Otherwise I would buy Rab. The Neutrino series look good or if you want a more durable bag then the Alpine series.