I'm running the faster Transcend MLC SSD in my X31, with Ubuntu 10.10. Compared with the mechanical drive, it feels a lot faster. I've got 1.25GB RAM fitted, rarely run into problems. Since I've got used to the performance of the revitalised X31, I keep fiddling with my X23 to work out why it's running so slow all of a sudden
There is a lot of tuning information available for Linux & SSD's, and to be honest it looked more convincing than the options available for XP - and I'm an MCSE of that vintage so not afraid of the steps involved.
Interesting performance benchmarks on the Transcend MLC SSD
here, and I bookmarked this
guide on optimising SSD performance (but of course there's other stuff specific to the netbook in question).
Neither the X31 or the X23 are a patch on my modern dual-core desktop for grunt, either in processor or video controller stakes, but the X31 certainly is fine for image editing, modern software, and a lot more than just emails

I wouldn't expect good results with HD video editing on it though.