We've sold 1 system with an XC201...XV and are now working on two more with the XC100 and XV-101-K84 character based HMI.
Our initial application is also using a VB.net app to extract data from the processor via the provided OPC server.
I think the visualization and simulation are fantastic. You really can simulate your whole machine before pulling a wire. Also, the Web server is pretty cool. As soon as my in house XC201 is not being used for some testing, I'll put it online for all to see.
If using with a Moeller MV4 HMI, DO NOT use the CANopen interface. Currently the Serial is the way to go; ethernet will be available around March they tell me.
We used the XI/ON remote I/O and that worked fine after learning a couple setup details but for some systems it would be cheaper to use another CPU as a remote I/O rack if needed. The CPU's themselves come with 8 Inputs and 6 Outputs (24VDC PNP interface). CANOpen is built into all the CPU's. Only the XC201 cpu's have the ethernet interface. Only the XC201's with the XV at the end have the Web server.
The controller does have file handling capabilities since it is based on Windows CE but these take longer to execute than the rest of the program so you have to account for this if you want to use them. But on the other hand, not many PLC's can write to a file directly that you can then offload from a built in ftp server. Note that the version of Windows CE it uses is closed. Thus, you can't run any of your own applications on it.
If you have any more questions please post.
**Disclaimer** I work for a Moeller Distributor.