So do the in/out temps (CPU Block) look normal to you for the CPU heat generated? I really expected more heat transfer than a few degrees?
That's just physics. Water has a very high specific heat capacity, of 4182 J/kgÂ°C, which is what makes it an excellent coolant. That means it takes a 4182W heater to raise the temperature of 1l of water by 1C in 1s, or a 418W heater will raise the temperature of 100ml of water by 1C in 1s (bringing the numbers a little closer to a CPU and water block). That's for static water (not moving), flow makes it more complex and raises the amount of energy needed to produce that delta (but the volume inside the block is much lower than 100ml). A couple of degrees delta across the water block is quite a bit of heat energy.
Should you repaste? Maybe, but the water temperature isn't really a good way to determine that. If you think you might have done a less than brilliant job with the paste, or you used crappy paste and now have the good stuff, or it's old, or your CPU seems to be running particularly hot or throttling; then repaste.