I would get the 3.0 Pro. Because it's a lot more quieter than the 2.0 pro. The 3.0 is 20.0 dBA and the 2.0 is 27.38 dBA. The 3.0 is also a lot more easier to install into a case, there is a lot of specs that outplay the 2.0.
Pros and Cons on the 3.0:
Pros
Will fit in the majority of cases with 120mm rear exhausts
Offers excellent performance for the small form factor
Fans offer excellent level of cooling performance
Simple and easy mount
4 pin PWM splitter if you have only one CPU PWM header
Flexible tubing
Fully braided pump cable
50mm Thick-rad
Cons
Fans are too loud at 1000RPM, should start at lower speed like 600/800RPM
Quite pricey considering for the same money can get you a Cooler Master Seidon 240M or 15% less gets you a Corsair H80i, Thermaltake could consider a slight price reduction
Fans aren’t sleeved all the way to the motor
Pros and cons on the 2.0:
Pros:
Great performance
Quiet operation
Hoses are very flexible
180° swivel fittings on water block
Little to no maintenance
Cons:
Installation was a little tricky
Thick radiator core may interfere with memory/tall components at top of case