Rumour has it that the Tomato firmware is slightly quicker than the DD-WRT firmware on a WRT54GL. Dunno if that's true or not.

But Tomato is supposedly good for up to about 25mbits/sec using PPPoE across the WAN link, so long as the firewall/QoS settings are not too onerous. At some point above that speed, it may become CPU-limited.

I have a collection of WRT54GL devices here, and all of mine happily overclock to 240Mhz (from the stock 200Mhz), which should raise that ceiling a bit. I do put heatsinks on them before overclocking though, out of paranoia. Others say that's not really necessary. YMMV.

Note that if overclocking fails on a WRT54xx router, it can be incredibly difficult to recover, because the boot-block sets the clock speed before the "failsafe download" stage.. and it all happens too quickly for a homebrew JTAG adapter to first gain control.

How do I know this? Heh.. heh.. a recent (mis-)adventure with my WRT54GS router: it didn't tolerate any amount of overclocking, and really wanted to become a brick.

So I had to open it up, and tie the highest address pin of the flash memory chip to +3.3V, so that the bootblock wouldn't be found/run at power-on, thereby allowing the JTAG adaptor to gain control. Then I snipped the pull-up wire (while still powered on), and used the JTAG to wipe the "nvram" parameter block from flash.

All in all, rather satisfying that this worked first try, with less than 10 minutes of effort!

Cheers