Sorry, long post...
We do Prochargers double digits in a year (37-1 over all other blowers), and support every install. We have PERSONALLY OWNed 2 P-1SCs and one D-1SC on my F-150s. My partner Mark has run the same P-1SC on two trucks for a matter of years before we went turbocharger.
We saw seepage, but no leaks unless the drain plug was not checked before install (YES cover your ass there BEFORE you install). The transmission is a machined fit, so this can be expected. Seepage means just that, resulting in a mist on the compressor over time, LEAKS mean draining the transmission and having to add oil prematurely. IF this occurs, you will notice a green tint to the oil. The volute could be sealed to the transmission with nothing but an Allen wrench, but this has not been necessary.
The GT kit comes with new crankase evacuation, and I will report any oil scavenging and post the fix IF I find any oil in the inlet ($2). A check valve on the PCV is normally in order on the older kits, and I will verify after a trip today. On this one, the you REMOVE the stock PCV hoses, they CAP the driver side vent, and the PCV is now a function of the inlet duct ONLY. You get constant CC evacuation ANYtime the engine is running. I say this because often CC oil is ingested at the inlet of the blower.
05 GT and F-150s... P-1SC-1. Different animal... BUT same basic construction as the D-1SC. The P-1SC-1 has the alternating STRAIGHT cut and HELIX cut on the impeller, which gives you a hard hit off idle (Straight cut blades) and another kick in the pants at about (HELIXED blades). This is more efficient on the top end than the P-1SC (ALL straight cut impeller for better off idle and midrange power. The 3 core IC FULL boost up to 15 PSI yeilds ambient charge temps (Dyno proven).
This and the 04-06 F-150 systems are COMPLETELY re-engineered, and NOT ONE piece is less than state of the art. A 5-8 hour install. It also includes a new fan, shroud, coolant reservoir, Predator, and 39# injectors. The best system I have seen them build! The best part? BLOW THRU MAF (The BOV came with a filter/muffler, but OOPS, left that off! Oh, and no trips to the parts store on this one, not even for a vacuum T!
Now, as for POWER... I no longer feel like I was born too late. This thing (BASE 9 PSI kit, custom SCT TUNE) is just like the 60s. In first at a 10 roll, you HAVE to modulate the LOUD PEDAL. If you don't, it stands up about a foot (Just like the good old days), and incinerates the tires... in 1st (1st is almost useless for traction), 2nd, and 3rd... Yeilding a yelp from the tires in 4th. IT IS ON just as soon as you hear the bypass close... If high 11s is not enough for you, I can get you 12 PSI or an 800 HP RACE setup. 3 core air to air IC is standard. Both the compressor and the IC can be upgraded as you build... Up to 30 PSI.
If you roll into the LOUD PEDAL, as soon as the bypass closes, it pins me in the seat, collapses the lumbar support, and then my head hits the roof!
It has perfect idle and drivability, but definitely loses it's manners when you go WFO!
I will get video and hopefully get to the track within the next couple of weeks.