Monitor Audio GX100 - How tough to drive?

Does anyone have any experience with these monitors and have an idea on how tough they are to drive?

I understand they need a lot more juice than the GX50.

Thanks in advance!
I had the GX200 and drove them with both a Pathos integrated and Bel Canto Integrated. I know it's not apples-to-apples with the GX100, but the Bel Canto-GX200 combo had so much low end, I actually got rid of my sub woofer.

I also had the RX6 and felt the GX200 were easier to drive than those...I currently have the PL200 and also had a pair of Silver 5i's...

What are you considering for power?