SMB UTM advice - cisco ISA570w

[fldevs]

I currently have a Watchguard xtm 22-w that is being over run by our increasing demands, the throughput was great until I added 4 more mobile vpn users and jumped to FiOS Quantum.

I am looking at Cisco's new ISA500 series, specifically the ISA570w. Any thoughts or options would be most welcome!