Mofimadness, The create tubes are reasonably priced compared to what I paid for my vintage Mullard. It is not an expensive experiment to try one out. Even if you don't like it as well as the Mullard, its probably worth having as a very good back up to have for when the Mullard gets weak.
I held on to my vintage Mullard because its not unlikely that at some point down the road, I'll find it has better synergy with my system than the Create, though I prefer the Create in my current set up. Also, the time draws near when the vintage mullards will be impossible to find, so I feel pretty good about having a good strong mullard sitting on the shelf.
The Create has its virtues. Very dynamic and a very low noise floor. Jet black background. Detailed, but not bright. It does not have that lushious, romantic, tubey sound, but surprisingly, I don't really miss that so much as you might expect. I encourage you to run the experiment and see for yourself.