If you need to be mobile then the Mitac 168 would be better for you. If you do however feel like a powerful PDA (mabye the Dell 624Mhz and Bluetooth GPS is better for you look at SiRF-Star-III based GPS like the holux 236
http://www.totalpda.co.uk/Holux-GPSl...receiver-.aspx
20 channel receivers are good but you will never pickup 20 satellites (well I have not ).