Hi,
I guess you questions is about having different WAAS models part of the same WCCP farm.
If that is the case, it shouldn't be an issue at all.
The only problem I would see with this is that if you have even load balancing, the less powerful device will be overloaded while there is still capacity on the other device
If you run into this, you might try to play with the WCCP mask to achieve uneven load balancing based on the devices processing powers.
Regards,
Nicolas
