LXDE has always been a favorite lite distro of mine. I recently installed LXDE with Linux Mint 17.1 as a lightweight backup / alternative to Cinnamon.
One of the little things I noticed is much of the functionality I like about Window List and App Grouping is just natively supported in LXDE. For example, the dock like feel can easily be created in LXDE by turning the window list into an icon, and grouping windows together. LXDE can give me much of the functionality I get in Cinnamon in a lighter package.
While I love my Rebecca there is one feature available in LXDE that is not available in Cinnamon or MATE. The window management of LXDE seems to recognize an instance of the Chrome browser from that of a Chrome App.
In Cinnamon, MATE, or LXDE when you click on a Chrome App it opens in its dedicated window. The difference is that in LXDE clicking the Gmail app will appear as Gmail rather than another Chrome instance. It looks like all LXDE is doing is grabbing the icon from the webapp instead of Chrome itself.
In navigating from Chrome OS to Linux Mint and back again, this has been one area of frustration. There are times I am running an app - that just happens to use Chrome - and I want my OS to treat it as any other app on my system. If I click Drive or Gmail on my panel I want it open in my window management as such not another instance of the Chrome Browser.