Hello Dmitry,
want to comment on your observations, as I am using a Multiface II too...
Dmitry Baikov schrieb:
  4) 64x2 @ 96k does not work at all. jackd gets killed
by watchdog.
 seems it can't start playing. 
can't confirm this. Works perfectly well for
me. Did large recording
sessions with 8 channels on 96kHz lately. For this, I did several
test sessions on my desktop PC (AMD64 X2 with debian / 64Studio). The
recording sessions itself I did on a 32bit Core Duo laptop with Ubuntu
Dapper and a multimedia patched kernel.
  128x2 @ 96k works perfectly. 
never tested this.
 5) if multiface box was power-cycled, firmware can't be loaded again,
 hdsploader gives:
 Upload firmware for card hw:0
 Hwdep ioctl error on card hw:0 : Device or resource busy.
 I have cardbus version, so the solution is to reinsert the card. I
 suppose with pci you'll need a reboot. 
same here, can confirm this.
But, on my desktop PC (with PCI card), power-cycling and the doing
hdsploader again works perfectly well.
Cheers,
Hermann Vosseler