I have configured a small system with 9 Cooper RF light switches and tested the following with an XP8 and T2-C.

Light switches
Light dimmers
RF Outlets
Scene controllers
HomeSeerer Software
Cooper RF Handheld, (the ugly blue lcd background remote hehe)
Cooper RF RS232 Interface

I have tested the system both in One way (MPIO) and two way (RS232)

I first tested the system with a one way system, i setup the lightswitches/dimmers/electrical outlets. I created scenes. I was able to get everything to work. I created my commands from scratch and put them in macros. The hardest thing was re-calling complex scenes or making changes to them. It can take some time doing it with the one way system. If you make a mistake, you have no idea what went wrong. It can be quite frustrating if you are not 100% familiar with the cooper command structure and the ligths are not doing what they should be doing.

Now for the two way... I created a different system, i was more interested in how zigbee remote re-acted to the commands as well how quick could poll the system from a sleep state.

I started with just one light switch and ran into massive issues. I created several icons/buttons. I created one button with a variable string text. When value=0="Off" When value=255="On". I created another button that was visible when on only. I created a toggle button with variable text (used from oasis template) and a slider/dimmer (used from the oasis template). The switch i used was not a dimmer, so i turned the slider/dimmer icon into a toggle to test.

I connected the RS232 interface via serial on the XP8. The biggest thing i noticed, and it probably is not the driver's fault is that xp8 can not poll the status of the lights when it turns on/resets or when the T2-C switches to that page with the buttons.

What this causes is the buttons not to work. When i switch to the page with lights it has the variable texts set to 0, the variable text are set to "off". The toggle with variables (oasis template) are set to off, and the slider/dimmer is at the bottom. Here is where you run into problems. When you hit any of the commands that should turn on the light, the variable texts change, to "On", the toggle button (oasis template) switches graphics, and displays "on". The slider/dimmer does not change and most disappointing the light does not turn on.

I believe the fault lies in the RS232 device. If you play with the buttons long enough the light sometimes turns on. Once it turns on, it syncs up with the RS232 interface and the buttons behave as they should with the correct text. Until you can turn on the light the buttons refuse to work, and its a guessing game as to when the remote can turn on the lights. I have the nodes setup correctly, but the remote has a very very hard time turning on the light.

The RS232 interface is very very limited functions. I know the cooper system quite well. When the light switches are turned on they broadcast their status and dimmer level (if its a dimmer) via the zwave. Any zwave device should be able to pickup the broadcast. I do not believe the RS232 interface or the light switches random broadcast or poll each other unless activated.

what it comes down to is a very un-reliable two way system, of which i am convinced it is not the fault of the driver. Cooper has a "Home Controller" which may offer better communication to its products, but the RS232 interface works well for one way system, but it doesnt work well for two way systems. I have tested using a baud speed of 11500, i will try the same system using 9600. and update this post with the out comes.