The water when its collected off the glass has a tds of about 50 - so not heavy on the filters ?
The ? is appropriate because it's unclear as to what type of filter is used for the recycled water. I think it's safe to assume that any pre-filters would be unnecessary as they would already have passed through those when entering a first RO (either in the vehicle or at a static unit). However, the next question would be as to whether it goes through an RO membrane before the next DI polishing or whether it's straight through DI. If there is water of 50 TDS needing to go through resin, my hope would be for a choice of a refillable vessel in preference to a sealed, colour change unit. In fact, I would like such a choice anyway.
A hands on demo wasn't practical at NEC and I did ask one of the Ionics guys some detailed questions about the functioning of the Pro 10. However, I didn't get detailed answers. I don't think he was being deliberately uninformative - more like he was rushed off his feet when I was at the Ionics stand and it was probably better to speak to a lot of people but in less detail than I was asking. The more laidback atmosphere of a roadshow should be helpful in getting more detailed info.