I use the original remote desktop from ms and I have to say its not that bad at all. It has a pinch to zoom that creates a small magnifier at the bottom of the screen making things slightly easier. The options are slightly gimped from regular remote desktop clients for the pc. You have to use unsecured access(xp mode) in the server for it to work. colors are limited to 256 color or 16bit and auto rotate does not work. for it to work in landscape mode you need to rotate the display before you connect. I find that full screen and fit remote desktop to screen does the job well enough though. Overall its very usable for those moments when you need to connect to a desktop/server on the go.
As far as the other remote desktop clients I haven't used them. I only have a license for the regular ms one.
Hope this gives you a slight hint on general shortcomings of the MS version of remote desktop.