As I understand it, although the access times are near instantaneous, the read times are quite slow. In other words, you get the first byte in a hurry, but it takes a long time to read a substantial number of consecutive bytes, so long that these devices are not suitable replacements for HDs in most applications even if the limited writes issue was resolved.
BTW, I was just at my local computer surplus retailer. He moves a lot of laptops that have been turned over by big corporations in an upgrade campaign. Most of them have smaller hard disks than are currently supplied with new laptops. He does a brisk business in updating them to a larger disk and more RAM to make them relevant. He was just informed that Seagate and Western Digital are bailing out of the parallel IDE laptop drive business in February. That's not good news given that 90% of current laptops use an IDE drive. The "also ran" suppliers e.g. Fujitsu may remain in the game, but he doesn't want any part of their products. He was financially burned by a run of bad 20GB laptop drives from Fujitsu. He ate the full retail value of over 300 of those bad drives.