I have a 4G surf, running Eeebuntu NBR 2.0, and it's a great little machine. Now it did not replace my Zaurus C1000, yet it has its own function in my computing needs. I am planning to replace the 4G with a 1000HA (10" screen, 1GB RAM, 160 GB HDD, Win XP [yuck, will install Ubuntu NBR on it])
Update:
Sold the EeePC 4G Surf. Got the EeePC 1000HA, and the 10 inch screen is great! Installed Ubuntu 9.04 on it, dual boot with Windoze (need it for some work related stuff)