Our experience as of late with customers and PCI has been that they have actually been able to sneak by using Windows File Auditing to pass most of the requirements, so LEM's FIM is certainly a step up from that Not much changed in PCI 3.0 regarding FIM, I added some PCI 3.0 notes to the bottom of our PCI DSS Requirements and Your SolarWinds Installations post on thwack not long ago that speaks to the notable/relevant changes we saw.
Strictly speaking, we have had customers using LEM's FIM that are bound by PCI, but I don't have details from their audits to know what was discussed.
Presumably if you use something like Linux auditd to track actual changes being made to files, it's similar to windows file auditing/real-time file change notifications (ref: Re: Support for Linux file auditing?).