hw.ata.wc vs soft updates

[Sergei Vyshenski]

Is it correct and/or clever to use BOTH

1) soft updates enabled and 2) hw.ata.wc=0

on FreeBSD-4.9 system?

Will it enhance chances to have consistent disk
after power loss?
How much slower it will be compared to the case of

1) soft updates enabled and 2) hw.ata.wc=1

Thanks in advance for any comment.
Sergei