.net packet capture: pcap.net vs sharppcap

interested in any comments anyone has around the various .net tools which can be used for passive packet capture. In terms of winpcap the choice seems to be between pcap.net and sharppcap. Another potential offering is Microsoft's NetworkMonitor and I am sure there are others as well.

I have used ethereal/wireshark as a diagnostic tool occasionally over the years but that is the limit of my knowledge. I'm looking to automate the capture process and subsequent diagnostic processing. I am tending towards pcap.net at the moment but would like to hear from anyone who has used two or more of these tools and whether they'd recommend one over another. My preference would be for the simplest interface/shallowest learning curve. Please let me know your thoughts.

Thanks Патрик