I use ObjectDBX - but I don't import the layer state: I look at it.
OK, let me explain. We have all our standard layers and layers states saved in a single "standard" drawing. I use ObjectDBX to import layers, but when it comes to layer states if you import them who also import ALL the layers: and we have over 400 standard layers (multiple disciplines). So what I do is open the "standards" drawing via ObjectDBX, change to the desired layer state, then compare the individual layer properties in the current drawing to mach the "standards" drawing. It works great. Let's say in the middle of a project one of a layers properties changes; linetype, plotstyle, etc. With my method the layer states are dynamic.
Now this is a real big mess of a program, but if you search here I know I've shared it. Search for "jbLayerStates" or "jbWorkingStates". My personal version is hooked into AutoCAD Architectures Project Navigator module but I'm sure I posted a simple AutoCAD version.
I'm not around here alot lately, but I'm sure there are others on here that use it. I hope this helps.
jb