Good resource but should be used as guidance
What do you like best?
Pathmatics is a good resource to see what media your competitors are running. You can see creative messaging across their media and a full breakdown of what websites they have media running on, along with impressions and spend. You can also see the allocation of spend/impressions across Display/Video/Social Media. Another helpful tool is the graphs they include, as you can see MoM or Quarterly spend across all sites as well.
What do you dislike?
There seems to be a lot of discrepancies with the media spend and impressions. I compared my client's media spend that was report on Pathmatics to the actual spend, and there were huge differences. Not sure what other discrepancies exist but the tool should be used as guidance at most rather than actual competitive insights. Another discrepancy I noticed was sometimes spend changes when you repull a report - for example I repulled the same report a week later and the spend was not matching the previous report.
Recommendations to others considering the product:
While Pathmatics is a great tool for guidance, be aware of what discrepancies may exist before making recommendations or adjustments to your media campaigns.
What problems are you solving with the product? What benefits have you realized?
Pathmatics was extremely helpful in seeing what creative messaging competitors are running. They have a catalog of all their historic creative, which is very insightful when doing competitive analysis and recommending what key messaging my client should keep in mind when building creative. The allocation in spend across different sites is also helpful as guidance when recommending how much money should be spend on Display vs. Video vs. Social Media.