I'm super happy with the AK240......it has blown away any all in one, as well as any of the stacks I have tried. I have not tried the 901 in any form. The next opportunity I will and if its better to my ears......I would change.
What I do keep searching for is a new custom. I've never heard of the NT6 till Mim wrote about it. IF I do change I am going to go with a silicon shell so there is some movement. I think it will increase the chances of a better isolated fit. Right now I have been ogling (a audio tech word:) the new Westone ES60.
If I could put some more bass slam into the Miracles I think I would look no more. I've tried EQ the 240 and it did not help any of the ways I've tried.