Question Which Cisco device is best

Cisco is not really in that market I don't think, unless they bought another company lately. They sell network equipment. They can monitor the network performance but not a employee performance. Unless you want to say see how fast someone downloads files I can't see what it would find. There are content filter things that attempt to limit internet traffic but this no longer works very well since everything is fully encrypted.

Even then what is employee performance. How many tickets they close or how many calls they take or how many lines of code that are written are very unique to the business application and not network hardware. This would have to have some method within the application to produce reports. All a network monitor can tell you is the user transferred 100mbytes day to say the source code server.

There are many companies that specialize in software that is loaded on the end client machines to monitor employees. They can tell you things like how many keystrokes per hour they are doing.....not that really matters for many jobs.