A lot of the well-priced aftermarket SSDs you see have multi-level controllers (MLC). Most of the SSDs you see built-in to laptops and netbooks have single-level controllers (SLC). If you Google, you'll find any number of articles about the controversy between the two and even controversy about the particularly buggy controller firmware for specific MLC drives.

You should also be aware that:
1. Writes are slower than reads.
2. "Excess" writing will reduce the lifetime of your SSD.
3. Windows generally doesn't perform well on SSDs.
4. Dell deploys Windows on their new SSD Netbook. I presume they've worked about the problems everyone else has with #3.

I'm waiting for:
1. Flash prices to come down generally. I have high hopes for x4 technology, which will allow the storage of four bits per NAND cell.
2. MLC SSD controllers to get better.
3. Me to get comfortable with running Linux instead of Windows.