The thing with Firewire, is for most things "consumer", it's a solution looking for a problem

Firewire is a complex interface, designed to minimise the overheads incurred by the host CPU, as all the low level stuff is handled on-chip by the firewire interfaces at either end

USB is a simple interface
all communications (including timing and collision stuff) is handled by the host CPU

Now, this means firewire is technically "better", but it also makes it more expensive

If you only have a few external devices (general consumer stuff - hard disks, optical drives, etc.)
you won't notice any difference with the protocol overheads
(now, 200 hard disks is different, but hardly consumer stuff)

Speeds are a non-issue
USB & Firewire are in a perpetual leap-frog, so either one can the "fastest" depending

USB 3 has a bandwidth of 4.8 Gbps, which is 6 times faster than Firewire-800 (and 3 times faster than Firewire-1600, and 1.5 times faster than Firewire-3200. But the higher speed firewire protocols are not common at the consumer level)

To be honest, for 90% of the market, firewire offers nothing over USB