IM 15 Owners -- Thoughts on rear chambers?

[xCry0x]

Tearing down my main tank and my wife, shockingly, suggested I get a smaller tank to keep things going.

The IM 15 seems like a no brainer since it looks nice and is a insane low cost.

That said, the rear chamber has me scratching my head.

Specifically that the 1st and 2nd chambers seem to be cut short by a plastic plate, which then creates a weird L shape for the 3rd chamber.

Seems like it unnecessarily limits the 1st two chambers in depth while creating a funky spot for cleaning in the 3rd chamber where it has to create an insane dead spot for junk to accumulate in. Wouldn't be able to put any type of bio media in there because I'd have to be fishing a siphon tube into the nook to suck out junk.

Is it a non issue for folks? Is it annoying? 

Other option would be a Waterbox 20 -- which is twice the price. Or the JBJ 20 which is also twice the price and includes a glass lid -- which is dumb and I'd want to replace with mesh anyway.