Tweaking always continues.... Got the Dremel involved this time! Plus my thoughts on the 800D and my 1 year experience in watercooling.
I cut holes and mounted my old 140mm rad from my HAF 932 setup. My cutting job is trash, but it was very easy. I'm surprised more people don't mount a 140mm radiator like this, it requires much less work than the typical 2x120mm rad mod that is seen on the 800D and you get to keep the bottom hard drive bays. My SB is now cooled by a 120mm rad and a 140mm rad. The 140mm fans that come with the 800D are quite wimpy. The bottom 140mm rad is soon to be replaced with a NB PK-3.
Sadly the results of my CPU loop are quite poor. I'm getting ~75C after a few passes of linx at 4.6ghz. The flowrate on the loop is significantly lower than my GPU loop, based on reservoir turbulence. I'll be tearing the loop apart tomorrow to check my CPU block and radiators. Also I might just need a reapplication of thermal paste.
Thoughts on the 800D in general:
A few months ago there was a quite a debate about the 800D in this forum. The conclusion was that it wasn't a great air cooling case, but it was a very good watercooling case. I am going to disagree with this statement. Instead I'll say:
Air flow wise this case really isn't that good and that effects both water and air cooling setups.
If we think about the air flow on a 800D, the only air intake is on the bottom of the case, aided by a low rpm 140mm fan. In my configuration I then have 4x GT AP-15s pushing air through the two upper rads. The amount of air intake is not enough for this sort of setup. With the side panel on the case, the amount of air coming off the top rad is significantly less than if your pull the side panel off. Essentially the 800D, in this setup, is very restrictive air flow wise. This also results in about a 5C difference in temps on my GPUs with the side panel vs no side panel. The NB PK-3 will help mitigate this problem due to its significantly higher air flow vs the stock corsair fans. But the problem still remains for many people running 3x120mm rads on the top of this case.
One year later:
So it has been a little over a year since I "got wet" and here is what I think.
1. Expense: I have spent roughly ~$1500 on my setup over the year. If you look through this thread you will see how much my loop has grown, changed, tweaked, complicated, and then simplified. I also bought frivolous things like thicker radiators and as a result have 3 spare radiators sitting around... Water cooling = expensive, but how expensive is truly up to you. My initial outlay was $500 for an incredible system performance wise. The next $1000 have barely lowered my temps, made my loop prettier, and gave me hours of joy and some frustration. No regrets
2. Maintenance: Maintenance hasn't been too bad to be honest. It is a little frustrating when it needs to be done since I have to dedicate about 10 hours to completely drain, clean, and refill the system every 6 months or so. To me however, that is a small price to pay. Honestly my system is "high maintenance" only because I keep changing it
3. Weight: This isn't a consideration that most people discuss when they think about the pros and cons of a water cooling setup. However, my computer is 80+ pounds fully loaded. This isn't trivial if you have to move your computer for a LAN or do maintenance on it. Rotating an awkwardly large 80 pound computer to get bubbles out of it can be quite precarious. This partially led to the death of my HAF 932. Got a poor hold on the case and it tumbled. Thankfully nothing leaked...
4. Leaks: I have had them. I lost a video card. It sucks to re-buying things. Use real hose clamps or compression fittings. Real hose clamps is why my loop didn't leak when I dropped my 932.
5. Joy: I absolutely love having a liquid cooled computer. Coolness factor and tinkering fun trump all the above issues in my book. Its an on going project. Something I can research and read about almost endlessly. I enjoy Admiring other people's liquid cooled machines and get ideas while also offering ideas based on my experience. Also, 2x overclocked 6970s @ ~40-45C under full load?

It is jolly good fun.
Edit:
Koolance RP-452x2 Rev 2.0
SIGNIFICANTLY BETTER! Koolance finally got it right with revision 2.0 of this bay res. Bleeding is so much easier with this than the previous versions. I am finally satisfied with the RP-452x2