Okay, 645LT is installed and connected. Let me just say, this is not something you want to do unless you're sure you need it. It was an ordeal and a half. That being said, this 560 is my first SFF build, so maybe it's just because I'm new to all this. Here're my tips to anyone looking to do this:
1. You'll want the 92mm holes to be as far towards the front of the case as possible - the last guy who did this and posted here indicated this. I was able to get this
bracket printed and it worked. The trick is, though, you need the holes as far forward as possible and you need the reservoir side of the radiator on the CPU side of the case - though it doesn't take a rocket scientist to figure this out, as it's the only configuration that will work.
2. If you're starting from an empty case, I'd recommend doing the fan under the motherboard first, then the motherboard (don't forget your mounting bracket, RAM, or CPU [and M.2s if you have them]), then the bracket with just the radiator on it (don't screw the bracket in yet!), the fan for the radiator (make sure you're doing an intake, not an exhaust), the GPU, 2.5 drives if you have them, the PSU, screw in the bracket, then affix the cooler to the CPU. The order on this is obviously flexible, but the cooler should be in the correct place before you install the PSU, and the bracket shouldn't be screwed into the chassis until the PSU is already mounted.
3. I listed this in my previous tip, but I'd like to expand on it. Since the reservoir side of the cooler is directly under the PSU, you'll find that the hose joints will interfere with the PSU cables. Pull the reservoir as far over to the CPU side as possible, and bend all your PSU cables toward the front of the case, and away from the hose joints. I had to smoosh a bit to get it into place. Just make sure you're not applying pressure on the hose joints at all, and make sure you're not putting stress on any connectors aside from the PSU cables.
Anyway, for performance. I'm running a 2600 with a .1v offset undervolt and a Gigabyte AORUS 1080ti. I now idle at about 40c for the CPU, which is a 10c decrease from the L9a. I ran a Strike in Destiny 2 with the GPU side panel on and capped out at 52c for the CPU and 85c(!) for the GPU. With the side panel off I capped out at 53c for the CPU and 79c for the GPU. For comparison, doing the same with the L9a and two Noctua Chromax 25x120mm fans with both panels on got me to about 70c on the CPU and 75c on the GPU. I ran Prime95 once for 15 minutes with both panels on and maxed out at 66c, and once with the GPU panel off and maxed out at 65c. I never ran Prime95 on the L9a, so I don't have a basis of comparison.
In short, when switching from an L9a to a 645lt for my 2600, idle temps dropped by ~10c, CPU temps in Destiny 2 dropped by ~17c but GPU temps rose by ~15c with the panel on and ~10c with the panel off, and Prime95 hits 66c after 15 minutes.
All in all, I'm quite happy with the performance of this thing and I'm feeling confident it'll handle what Zen 2 throws at it. I will be ordering a vented side panel for my GPU side, but with the absurd cost of shipping, I'm wondering if I should wait until the handle drops; as of right now I'm looking at $22 shipping on a $20 item for the cheapest option, which is a pretty tough pill to swallow.
@KSliger, I know these have been asked, but I don't think I've seen an answer yet, but do we have an ETA on the handle for the 550/560? Also, are there any plans to bring down shipping costs in the near future?
Edit: Here's an album: