Deep into research on new pool robot. Dolphin looks good. Agree with whomever said buying from them and tracking different models is like buying a new mattress. Anyway I live in Seattle and have a problem with leaves on the bottom of the pool in the spring and in the fall. I see that the M500 or M400 would be considered the top of the line Dolphins, but both use cartridges and I worry that they will become clogged with leaves quickly due to not enough reservoir space. The DX6 looks to be a little older, but uses filter bags rather than cartridges, which I presume will allow it to pick up more leaves. Ultimately I'd like to have it all - from fine dust to leaves - in one machine.... if that is possible. Does anyone have experience with and recommendation for this particular issue? Thanks kindly! Sam