Yuki how do you like those G6 systems? I've heard mixed reviews.
It's run extremely quiet, you barely hear anything even you right at it, mechanical filter clean easy and fast, reusable and durable, huge bio media chamber (all 3 baskets are bio media section), chemical chamber can be another bio media section if you don't use carbon or purigen (I put pond matrix in there), display alert when things need/due for clean up are helpful. I don't have any problems with these Fluval G6 yet, I got them a bit over 2 years, its works flawlessly and I have to say my money well spend on those filters.