Can you explain your reasoning?
Both are solid performers. Either would be fine, and if there was any advantage to one or the other, it certainly would not be "far and away".
The PDX1 is very similar to the RangerT rounds. Those are some of the best SD rounds out there.
It's similar to the Ranger Bonded rounds, but those are nothing like the Ranger-T rounds. They use two completely different bullets. In all honesty, after reviewing the ballistics on Winchester's site, I would not be comfortable carrying the Ranger Bonded rounds.
As to ballistic testing, Winchester's own site shows both the 124gr +P and the 147gr Ranger Bonded bullets failing nearly all but the bare gelatin tests, and then they are nothing exceptional, although the 124gr +P does show promise in that single bare gelatin test.
Winchester PDX1 147gr Testing on YouTube
This video shows the 147gr PDX1 bullet in denim testing; it travels 17.5" in wet newspaper jugs covered with 4 layers of denim and expands to only 0.50" which is abysmal when compared with premium JHPs. In the bare water jugs, the PDX1 expanded to .56" and penetrated to ~17.5" (water test is inexact). It did stay together, so I can't fault that, although I find any rounds penetrating deeper than 15" or 16" to be a bit much. FBI standards say 12"-18," so it does fall into that category perfectly fine. However it still fails in terms of expansion and is wholly underwhelming for a modern JHP.
Federal Tactical HST 147gr Testing on YouTube
This video shows the 147gr Tactical HST bullet in similar testing. The first bullet is fired through denim into wet newspaper jugs and penetrates to 16.0," and expands to 0.70," which is phenomenal. The second bullet is fired into bare water jugs where it penetrated from 13" to 16" (water test is inexact) and expands to a whopping 0.75," which is more than Winchester claims their .45 ACP 230gr Ranger-T bullet expands!
In closing... The PDX1 is a mediocre SD round, especially with so many great options available. I'd never watched that video before today, so I can honestly say that I didn't know the PDX1 was that underwhelming in terms of expansion. Would you rather have similar penetration with .75" of expansion or .56" of expansion? Not to mention the PDX1 costs $25 for a box of 20 whereas the Tactical HST rounds cost $29 for a box of 50, so you could practice and stock much more of it, unless price wasn't an option.
I hope this helps.
P.S. From Winchester's website, "The new Winchester Supreme Elite Bonded PDX1, which was chosen by the FBI as their primary service round, is now available in a full line of popular handgun calibers. The Bonded PDX1 is engineered to maximize terminal ballistics, as defined by the demanding FBI test protocol, which simulates real-world threats. The new Winchester Bonded PDX is offered in 9mm, 40 Smith & Wesson, 45 automatic and .38 special."
The FBI service round is a bonded 180gr .40 S&W round developed by Winchester, this much is true. However, this round cannot be anything like the .40 S&W Ranger Bonded as that bullet failed testing and failed it miserably. If the FBI saw the results I'm staring at, there is no way they'd accept them, which means the PDX1 (if it is actually the same bullet the FBI uses as Winchester claims it is) 180gr .40 S&W must be exceptionally better than the 9mm testing we just witnessed, as no LEA I've heard of would accept those as their primary duty load after comparing them side by side with the HST, Gold Dot, Ranger-T or DPX.
I do find it very hard to believe that Winchester would offer the round the FBI uses to the public in free form when their Ranger-T boxes are specifically marked as "Law Enforcement Only," and gun shops are not allowed to sell them to civilians. ...Just a thought.