I eval'ed TippingPoint's IPS appliance...
i think it did great for what it is meant to do. no network slowdown, immediate results. easier to install than a blank hdd into a PC. hell, easier to install than a dsl mdm to a router to your small network....
Dell Precision WS470 Xenon 3.0GB 1GB PC3200 80GB SATA HDD
but...control 5 servers, one switch rack with 300 ports protected by cisco router, 300 PC's, 75 notebooks over a wLAN ;)