Okay, here goes. Spoiler alert: first post and a brief review of a case I really like.
I've been a proud owner of the Core P7 TG for some time and when I saw the P8 it addressed my major concern regarding the Core P7: the P7 has no possibility to have fans blow over PCIe-Cards and RAM if you do not want to install the "wings" just for this purpose. Since I do employ a number of PCIe-Cards, the Core P8 was a "must try" as soon as it became available.
As you may have guessed already, I will be comparing the P8 to the P7 quite a lot.
Interestingly, the packing is almost exactly the same size, but where you had to assemble the P7 yourself (at least the feet and the window-mounting) the P8 comes fully pre-assembled. The P8 is also a bit larger. The baseplate is basically exactly the same as with the P7 (albeit a bit larger and I will come to one nuissance later). As you can see in the attached pics, the hardware is still in the P7.
As you can see in the following pics, the P8 is even larger than the P7 (hardware still installed in the P7):
As you can see here, I had two 140mm fans fumbled in also in the P7:
Tiny but welcome detail: the screws to secure the back do not have to be removed completely - don't know the technical term but they remain with the metal backplate without falling out and the backplate is no longer slid sideways for removal but just pulled off straight. Definitely more convenient than with the P7.
Unfortunatly, quality control missed an ugly scratch, probably from a screwdriver when the case was assembled? Ah well, it's at the back and I won't see it, so I don't care too much. But still... meh.
What I do like is the mounting bracket for the front window: with the P7 you had to grip & balance the window with one hand while turning in the first two screws with the other. With the P8 you just insert the window and have both hands free to work. Noice, me likey.
The interior is really alsmost the same as with the P7, except for the radiator/fan mounting as well as glas side panels obviously.
I do like the included mounting plate for watercooling pumps and/or reservoirs: I can confirm that a stand for the Watercool Heatkiller Tube will also fit perfectly (sorry Thermaltake, no need to buy yours ;))!
Turning to the "dark side", I really do like the changes made here: the drive cages... or rather plates... now fit two 2,5" drives compared to just one with the P7. However, we lost the possibility to mount 3.5" drives without screws as we could with the P7. I also appreciate that the drive locations have been moved from "behind the motherboard" to the lower area. Now we do not have to disassemble all three drive-cages as well as the underlying mounting plate for cable management. In fact, all cables can be installed without missing a beat. Good job!
There is just one "BUT". Why did you place the motherboard so far inwards? You can't even properly reach the screws to attach the slot... errr... dunno how to call it: slotplate? in its normal position. I had to remove the slot braces and get to the screws "from the inside". Also, attaching cables both in PCIe-cards as well in the IO-field of the motherboard is a real pain if the rear is not freely accessible at the case's final position (as was the case with me, unfortunately). I broke approx. 3 fingers and cursed numerous times while trying to attach USB, network and all the other stuff. There is plenty of room to move the mainboard further to the back and maybe even fit the IO-shield. As it is now, I don't understand why you only made room for a 120mm fan there - the space you spared did not really make a difference when trying to plug something into the motherboard there. So, unless I am missing something, why not move the board location further back? By the way, if you did this, an EATX mainboard would also not block most of the cable holes to the right... (again cursed quite a bit when I installed a ASUS Prime X399 EATX in my P7 some time ago).
Finally, another suggestion if anyone from Thermaltake is reading this: even though the case screams "internal watercooling!" - why not provide for two holes to properly route water cooling tubing out of the case? For examble, you could put in a larger hole at the bottom - as it is, a 16/10mm tube fits easily between the stand and the case. There may be others like me who just love their external monster radiators while still loving what the P8 has to offer! As it is, the tubes are currently dangling somewhere behind the PSU and that just doesn't fit with the overall awesomeness the P8 brings to the table. The final pic shows the current build (pulled from a P7) - it's pure quiet functionality, I hate RGB (but like those shiney build of others - it's just not for me).
For those of you who want to know, here are the specs: Threadripper 3960X with WaterCool Heatkiller IV Pro for TR Copper Nickel, ASRock TRX40 Taichi, 64GB Crucial Ballistix MAX 4000@3600/16/17/16/34, 2080Ti FE with WaterCool Heatkiller IV for RTX 2080Ti Acryl, USB3 addon card, Mellanox ConnectX-4 Dual 100Gbit NIC, 1TB Samsung PM961, 4x2TB ADATA SX8200Pro on Asus HyperX (Raid0), Seasonic Prime Ultra 1300 Platinum, Aquacomputer Aquaero 6 Pro, Aquacomputer Flow Sensor "high flow USB", 4x Noctua Chromax 140, 1x Noctua Chromax 120. (Not on the pictures: 2x WaterCool Mora3 420, WaterCool D5 Vario pump, WaterCool Heatkiller Tube 200 for D5,)
Yeah, besides becoming somewhat of a Thermaltake-case-fanboi, one might say I'm a WaterCool fanboi for all things "water cooling".
So, thank you Thermaltake for the P8. I love it and the "buts" as well as the suggestions are just my thoughts on how you might still improve on what is already a really great case.
Oh, and I paid for it myself. Just in case (pun intended).