Why any one would pay 600 hundred bucks for any handheld when they could get a Tungsten T for 300 dollars I personally don't understand...
All depends on what someone wants. An iPaq 54xx series ($600-$700) gives you built in 802.11b, more memory, a faster processor, biometric security, and a ton of expansion options that are out now. An iPaq 1910 ($300) will give you about the same features as the Tungsten, but still a faster processor, and more memory. The upcoming rumored revision will add Bluetooth as well.

Palm to me was great ages ago back when the PocketPCs were still trying to find where they fit in the market. Now it just seems like Palm is playing catchup with both the PocketPC camp, and Sony.