TDM II is really quite a different bus, so it is hard to make apples to apples comparisons. While in the absolute worst case TDM II "only" has twice the slots (at 48k), for most real world sessions it really is much more than this. First, TDM II is a bidirectional bus that has 512 slots (256 slots at 96k) running "down" the bus and another totally separate set of 512 slots running "up". In a sense this is really like having 1024 slots, as long as the amount of communication "up" is fairly even with the "down". Also, slots can be "reused". Meaning that if you need a connection between DSP 1 to DSP 3 and another connection between DSP 5 and DSP 6, TDM II will just use a single slot. It is not uncommon for slot "reuse" to result in 2x to 4x improvement in slot usage, although it will definitely depend on the session. Putting these two factors together the bottom line is that with most sessions slot usage will be greatly improved on TDM II.