Depends on whether your use of Firefox is for Javascript or server-side scripting. Running heavy non-minified Javascript with caching disabled is much more pleasant on a fast machine.

Run Firefox on the server and export the display over the network to the weedy laptop.

Depending on the technology used, exporting sound can be an hour of fiddling about to get it setup first time around.

I'd rather get hit in the crotch than use Firefox over X forwarding. Slow on top of slow. There is some interesting work with NX and NX-like solutions that make it much more tolerable.

Haha :) I keep going back to X over SSH.

Out of VNC, RDP and NX, VNC is the lame duck.

Out of RDP & NX, both require extra software but RDP is more widely re-usable (virtual box, windows etc).

The bandwidth requirements aren't the problem with X these days - a 3G connection at under 1Mbps real world is fine for reasonable display sizes, it's the round trip latency is the killer. It's such a chatty protocol, but on a LAN / WiFi it's fine and works out of the box with... scratch that, you need to install XQuartz separately since Mountain Lion. I almost forgot about that.

nx is way faster than rdp if you have a large display

> it's the round trip latency is the killer

Yeah, my understanding is that NX mimicks the remote end locally and then translates the result and transmits that. There's an Android app called BVNC that uses X forwarding with a local X server to do the same thing. No extra software and it's more responsive than X-forwarding.

I should've just mentioned it before, it may be of use to you.