Moving from VMware Server to ESXi

At home I'm currently using VMware Server with Windows 2003 as the host OS. In addition to running 5 guest operating systems, the host OS performs the following tasks:

• Shuts down the server in the event of an extended power outage thanks to APC PowerChute.
• Backs up the VMDK files to locally attached USB hard drives.
• Allows remote administration via Terminal Services (Remote Desktop).
• Hosts my complex virtual networking services including NAT (with port forwards) and routing for the virtual machines.

Lately I've been reading up on VMware ESXi and it appears as though my existing hardware is going to work, however I'm having a hard time deciding if the extra efficiency is worth the hassle. From what I've read I will have to find a different way to perform backups since local USB devices aren't supported, in addition I will have to provision a VM to perform the NAT and routing duties. On the other hand the I/O struggles at times with VMware Server so the extra performance and stability from ESXi would be welcomed; I've had VMware Server's NAT implementation crash twice during 18 months of use.

If anyone out there has made the move, I'd love to hear their experiences and feedback!