I have had my E10 on the second opening now and it beat my Aquabot Rover hands down twice over for this kind of dirt.
I don't cover when closing so opening, cleaning is a little more involved that when I use to cover. On the initial clean, I don't have trees, but after a lot of wind I get a few neighbors , so I use the leaf net.
I then use the E10 with the original basket that it is supplied with for one run. Then I brush pool, let everything settle for a day , next day I run the E10 again, although pool may look clean there is alot of dirt still in there.
Next day I use the E10, but with the optional ultra fine filter box, a little pricey, but way worth the price, this filter will pick up the type of dirt you may be speaking of, the type of dirt that passes through all other type of filter bags or even the original E10 supplied filter box. I found that if you try to short cut this process by just using the ultra fine filter at the start, it will plug fairly fast and start to go buoyant, and you will be removing the Dolphin from the water every 10 minutes just to clean out the filter. I rarely use my Pool Blaster Max anymore for spot cleaning, the E10 with the ultra fine filter box is good enough once a week. Last year when opening I was just as frustrated as you and could have hooked this thing to the back of my Jeep . It was my own fault by jumping straight to the ultra fine filter. the old cliché ! trust me

, love this thing.