Sure, Tomato is simple and pretty looking. Apart from the IPv6 issues mentioned by others, the biggest issue for me with Tomato is that it doesn't support VLANs on Broadcom hardware. OpenWRT and DD-WRT both support them, and OpenWRT is really open, so I use that. The live statistics graphs and such in Tomato have an equivalent package in OpenWRT.

Note that also, there exist 4GB SD cards as well as 4GB SDHC cards, however for devices that don't support SDHC, support for SD cards larger than 2GB is hit or miss. The SD standard actually supports up to 4GB, but as happens all too often, signed vs. unsigned values are ignored/interchanged and some devices don't support the 4GB standard SD cards.