The problem I run into using Metro RDP on my Surface is that I remote into work and when I want to switch apps it is far easier for me to swipe from the left and change over than it is to go to the taskbar with a mouse and change apps. Also, I like the way all the remote machines are placed in the context bar that pulls down from the top. I find this easier to switch from machine to machine than going to the taskbar and clicking. I also like how metro RDP auto-resized the remote desktop based on the snap size of the RDP app- this is not possible with desktop RDP as it keeps the window at the same size and just adds scroll bars- not very touch friendly.
I am not saying that desktop RDP can't be used, but that I am using a hybrid device, and as such the apps I use are used in a hybrid method- with both touch and mouse at the same time. I can't do that in the desktop RDP client. It is just not possible. I don't use mouse only- I have had a touchscreen laptop for many years- since 2008- I am very well accustomed to how to use touch and mouse at the same time- Windows 8 has taken this to a new level with greater ability to use touch. This title bar has removed some of the ability to use the mouse on a touch friendly app.
If metro RDP were only designed for touch then it should not be possible to remote into any computer that is older than Windows 8, and even then should only be allowed to be in the metro UI. It is ridiculous to think that the app was designed for touch only- it is just not possible to use touch only when remoting into a Windows 7 computer- especially on a 10 inch screen.