The PO1 is touted as having improved metallurgy than the PCR, but the PCR was certainly tough enough to win Czech National Police approval. The PO1 reportedly has a forged alloy frame as opposed to the PCRs' cast alloy frame.
Cast or forged, I have both the PCR and the PO1, and both are outstanding pistols, reliable, durable, and accurate.
The CZ-75 Compact is a steel frame pistol, is also available in 40 SW - but the .40 comes with the M3 rail. The major differance is the Compact is traditional CZ DA, cocked and locked, or half cock carry. I prefer the half, where the decocker on my two drop it.
I carry the PO1 every day, IWB and OWB and the M3 rail doesn't bother me in the slightest. A good holster will remove that complaint.
Grips...well, I can't help you there.
I will say the original rubber grips on the PO1/PCR do work quite well, better than the plastic. Still have one original
The 14 round mags can be slightly difficult to find, and more expensive than say, 1911 mags, but I even found one rare one marked LE only from the ban era...no Compacts were adopted by an LE agency during that time.
The RAMI is a good solid pistol, one my wife loves.
With the extended 14 round mag, it becomes very easy to shoot, and still conceals well.
After all is said and done, maybe this expresses it best....