Would firewire networking be better than 100Megabit ethernet?

My office network has a fully switched 1000Megabit ethernet network. I have an Apple iMac with a Gigabit NIC and FireWire, and a Compaq laptop with a 100Megabit NIC and a 4-pin FireWire interface. Accessing my office's shared drives using my laptop is (obviously) much slower using my laptop than my iMac. Would I see a noticible performance boost if I enabled Internet Connection Sharing on my iMac and shared the private ethernet network from my iMac with my laptop over FireWire? FireWire is 480400Mbit/sec, right? So would I see roughly 4x speed improvement with such a setup?

EDIT: OK. Having set this up I find that performance is actually worse when copying a file from a server on our ethernet network to my laptop, when my laptop is connected to my iMac using FireWire. I suspect this is because of NAT on my iMac slowing things down?

I got about 5.9 MB/sec when copying a 100Meg file over 100Megabit ethernet, and only 3.6 MB/sec when copying the same file using firewire <-> iMac <-> ethernet. But when going between the iMac and the laptop using FireWire I get 11 MB/sec! So it must be NAT slowing things down then, huh?

Sure. For point-to-point FireWire is great. Unlike USB, FireWire controllers have brains and can handle data transfers easily. Do be aware that CPU usage will go up though.