I like this question. No experience with the Phantom sadly, but maybe one day.
After about a decade and a few samples of each (SP01, P09, P07, P01) I went with the metal frame 75 series and that’s after running USPSA, Steel Challenge, reactive drills/shooting drills, run and gun, etc.
I have small/medium hands and the polymer P series is too thin side to side for me to get a good support hand position, without or without skate tape. Metal frame 75’s with slim grips are a whole other story - the meat of my support hand palm can get slightly behind the gun which increases my personal recoil control and follow up shot consistency.
I prefer to modify grip width (with side panels/stocks/standard grips) vs modifying backstraps.
The slides are larger on the polymer P series, and that mass slows down sight tracking (reportedly) for some. I will say I prefer the “faster” cycling of the 75, it may be more abrupt but I process it better. I never found any real substantial difference in slide racking between the polymer and metal frame models, but I will say the mag wells on the 75 (when they have beveled mag wells) have been much smoother and faster than with the angular sharp P series mags even after whittling on the plastic mag well.
Sometimes I’ll eject a mag and do some mag change drills because it’s that satisfying with MecGar mags in a PCR, P01, SP01 etc.
I’ve had smoother triggers in the metal framed guns, which matters ALOT to me as I’m carrying it DA. This is with CGW/CZC parts. I suspect the 1911-esque trigger bar of the 75 plays a role in a smoother trigger.
All in all, I’ve seen good work done by the P07/P09, but the 75 series was simply the “easy button” for me. YMMV.