I received it, looks and feels great! My only problem is, how the hell are you supposed to change the length of the cobra belt and still keep the battle belt centered? So much velcro I can't possibly pull the inner/outer belt to one side to center it!

If you mean separate the Velcro bond between the inner and outer belts so to adjust or move them in relation to one another,

Lay the whole thing out flat on a flat surface and use a slim, rigid piece of plastic or something that can go through and split the Velcro and keep it separated while you adjust, something like a wide yard stick or I would probably cut a piece of hard plastic sheeting down to do it.  Then once you get the two components re-aligned, hold them in place and slide out the insert you used and let the Velcro re-bond. 

Here is a video showing how you can use the stiffener in the outer belt as your insert to do this on the Sure-Grip belt, not sure if the Slim-Grip has a similar insert, but at least it shows the concept.

lowes sells a nice 3ft long flexible aluminum yardstick for something like $6. you can insert this between the belt and the cobra belt and reposition accordingly. i use it all the time. works flawlessly

No need to do that.  Use the included plastic stiffener.  Works great.

This. I think that's half the reason it's included 

I thought that's what that piece was for I didn't realize it was a stiffener. The slim grip does come with one as does the suregrip. I just transferred everything from a suregrip to a slim grip last week.

I had both as well, I ended up switching to a Volund though.