I was looking at the Sheevaplug and the Guruplugs, I didn't like the one USB on the Sheeva and the loud overheating expensive Guru. So I ordered the Dockstar, I paid $28 shipped, vs $99+tax+shipping on the Sheeva and an even higher figure on the Guru.
Also, I have a USB 500GB harddrive, I really was nervous powering it off the Sheevaplug and I was thinking of making the plug a router so adding a Ethernet USB, and when I added the USB powered hub, it was getting expensive. With the Dockstar, the PSU is external and the 3 USB are powered, so that's saving me some costs.
I have Sheevaplug, with the stock optimized Ubuntu, in the context I was using it, 128MB is enough, it was running 80MB utilized with the apps I use. I have actually been trying to reduce FLASH wear by using memory more, and placed the proxy server cache in memory with a 300MB limit, as I could not get all the memory used. My advice is not get too hung up about 128MB if you're not running too many apps.
Linux is so memory-efficient, I reckon Kingston much have done the Venture Capital for Microsoft, all the memory been bought for Redmond's bloated code.
I'm a little nervous doing the physical serial thing with the Dockstar, I've not touched terminals and electronics for years. I liked the Sheevaplug approach. My Dockstar is going to file-server, I might offer it to some UK folks as a proxy server so they can Hulu, and it will be doing torrents so I can shutdown the PCs and save on overnight electricity. It should pay for itself in a few months of reduced utility bills.