Yep, the wagon rides really nice with the E500 front struts using stock wheels/tires. I'm going to upgrade the wheels soon so I'll let you know if the ride becomes firmer as I move up in wheel diameter.
I still haven't figured out what to do with the back...still running the stock wagon SLS. It's too soft in back, I think the struts are worn out but I've never heard of that happening, especially with only 92K miles.