The original series H150i Pro didn't have the RGB fans and is pretty much discontinued in favor of the newer series that does. The original fans were a new series, the ML 120mm, mag-lev (not supposed to use that, it's copyrighted) magnetic levitation which supposedly provide a super quiet and extremely long lasting and reliable bearing, as there's almost no friction. The LL series doesn't have that.
LL 120mm: 600-1500 rpm, 43cfm, 1.6mm/H²O
ML 120mm: 400-2400 rpm, 75cfm, 4.5mm/H²O
Id say you are going to loose out on a considerable bit of performance, especially during heavy gaming or other hard cpu, the LL's are going to ramp higher and the cpu will be a few °C warmer at anything but idle. The LL's push just over ½ the amount of air, at ⅓ the static pressure.
Considering that aio also doubles as either an exhaust or an intake, that loss of cfm/sp across 3 fans is going to hurt.
What's bad is the ML120mm Pro RGB are 400-1600 rpm, 47cfm, 1.8mm/H²O, so a little better than the LL RGB, but not even close to the non-RGB Pros in performance. Pro reviews say pretty much the same, performance took a dump with the inclusion of the RGB.