Originally Posted by
D-S-J
I only have experience with 2 AIOs so far. The EK Predator and the hybrid cooler on my EVGA GTX 1080. Since you're not interested in the expandables, I'll share my experience with my hybrid cooler.
The hybrid cooler is my by Asetek with EVGA branding. I removed the stock fan and replaced with with 2 Noctua's in push/pull, performance did increase slightly. Not a night and day difference though. From an acoustic performance it was much quieter even with 2 Noctuas over the single stock fan.
Slapping a good fan on a cheap AIO isn't going to gain you that much more performance for the additional cost.
Though cheap or expensive is subjective. $150 is about the average price for 280mm-360mm AIOs from the mainstream brands. You'll likely get decent fans within that price tier.
Don't rule out expandable AIOs. Mainstream brands are leading towards that way even though others are already there. Even mainstream mid and high tier AIOs have G1/4 fittings and proprietary interchangeable parts. Maybe we'll have more quality AIOs from mainstream brands similar to the following.
This type of AIO from Aquacomputer does rival some custom loops in terms of performance and customization. Cost does put this beyond the mainstream.