I did the work around with other phone as well, not just my 8525. I did it with my old Motorola Razr and a Samsung something from Sprint. Same story. One contact at a time. The 8525 turned out to be the fastest. It connected just fine with my ES and I'd go as far as to say that the two are compatible.
I'm still happy with my ES. I am very grateful that Lexus took a long hard look at how counterintuitive the old BlueTooth, Nav, and voice recognition was. They seemed to have fixed many things in the 2010 model.
Anyhow, my contacts are now transfered, and as it goes, it took more time opening and discussing this thread than it did to just transfer the contacts one at a time.