Hmmm... well it will certainly work fine, however I would have to say it's unnecessarily complex. It appears you are using tubing runs to make sure you have a radiator after each block - however in practice this actually doesn't do what you think it does. On your diagram you indicate 'hot' and 'cold' sides... which seems right but in reality the fluid temperature will equalize rapidly regardless of component order. I know it probably doesn't seem like that works... but trust me it does. I used to think I needed to have my CPU always first in my loop because it generated more heat and needed 'cooler water'. Now almost every build I do has the GPU(s) straight off the pump and straight into the CPU... followed by all the radiators... and the temperatures are exactly the same.
I would just run the GPU blocks together (if you put two tubing runs between them they'll be parallel and it will flow a little better).You might consider a run like this: Pump->CPU->Top Radiator->Back Radiator->Side Radiator->Top GPU->Bottom GPU->Reservoir
(The main reason I suggest this order is you wouldn't have to change as much of your loop as the first part is already in place this way... if you redo everything later I'd just run from the closest block/radiator to the next closest unless you're doing it for looks more than performance.)
That would make the runs cleaner and shorter and wouldn't change the cooling capacity at all - in fact, it might cool slightly better
as there will now be a little less restriction and there will be much better airflow through the case to help cool anything that doesn't have a block on it.
That being said, welcome to watercooling!
(And definitely just enjoy using your build before worrying about the next update... once you start, it gets very addictive!)Edited by DiGiCiDAL - 4/13/17 at 2:28am