I'm going to post a new thread, but my experience with DxO regarding the Nik Collection has been awful. I have been using Nik since 2009--before it was purchased by Google--and when I finally upgraded my PC and OS and Photoshop, I had to buy the Collection. $150 was the price, which was what I paid for Viveza 2 back in the day, so that's OK.
Five weeks later, Collection 3 is out. The upgrade price is $50, and the fresh-install price is $100. I purchased Collection 2 just a couple weeks before their cut-off date for free upgrade, and they are completely unwilling to make an exception--even though the price of Collection 3 is $50 less than what I paid for Collection 2.
My bottom line is that the Nik Collection is really good--though DxO has cocked-up the interface a bit--and definitely worth $100. Silver Efex itself is worth the money--it's the best B/W converter out there (the film grain choices are fantastic) and is amazingly flexible--so buy now. But don't trust DxO to be even remotely accommodating to you as a customer.