Deciding what fans to use

[CrepusRay]

I am looking to buy a corsair iCUE H150i ELITE LCD, I also want to get the corsair LL120 rgb fans, but I have seen a lot of discussion that the LL120's are bad for radiator cooling, I have an intel i7, I am just wondering how good/bad would the corsair LL120 fans be on the cooler

[Corsair Notepad]

In terms of cooling performance with an AIO the fans that come with the cooler will perform better than the LL RGB series fans.

[c-attack]

Unless you have a high TDP Processor that you will keep at near maximum loads for folding, encoding, etc., the 360mm radiator allows you more flexible choice of fans.  The difference between an average fan and a stellar one might only be 1-2C on a 360mm. This is different than a single panel radiator where fan choice is critical. 

[CrepusRay]

I would be getting the 360 one

 

[CrepusRay]

So you're saying that I could go with the LL120s instead of the MLs and I would only see a very slight differernce if any?

[Corsair Notepad]

If you wanted to go with the LLs for aesthetics, you can do so with minimal impact to cooling, but the ML Elite fans that come with that cooler will perform better than the LLs in an apples-to-apples comparison as they are designed with use on radiators in mind.