I've been trying to consolidate several remote and local accesses into a single remote desktop client, partly to reduce the number of tools I have on the taskbar. Target machines are mostly Linux Mint (Maya) plus a local Windows 2000 server and a remote Windows 8 (2012) server.
I found Remmina, based on xfreerdp, to be the best option with the following caveats:
Windows 8 server: no apparent problems using RDP session. There is a problem accessing a Hyper-V Mint server through this, though. Mostly it works but there is no copy/paste (clipboard) or middle-mouse-button slide control (both work in windows, though).
Windows 2000: using RDP, does not like a second login (eg after accidental window closure leaves windows with more than one session live). Solution: open a new windws session with gnomeRDP, close the sessions, then return to remmina. Not sure if this also applies to windows 2003/XP.
Mint: RDP works up to a point with remote xrdp, the point being: no proper keyboard layout, which means some keys such as @ and " are reversed making even login difficult; copy/paste across the session does not work (well-known clipboard problem going back ages and mostly unfixed!). A shame because I prefer RDP to VNC. Using VNC (vino on the remote machine) fixes these problems but is slower and sometimes one has to move the mouse to make something show (eg click on Menu, wait for a while or move mouse for immediate response).
One other fault I've found on remmina/VNC/vino is that sometimes MySQL Workbench freezes. The solution seems to be to drop the session and reconnect - old session is still open but freeze has gone. I know it's VNC that's the problem because one of the Mint machines also has access through a remmina Windows 8 Hyper-H session and MySQL Workbench is unfrozen on that.
By and large, in my opinion, remmina is not especially suitable for linux-linux use but is probably the best available if you want a GUI client.
GnomeRDP works well with older Windows machines (eg 2000, 2003) but cannot connect to Windows 8 (2012). It does not work well linux-linux.
It would be nice if there were a single GUI that worked properly with all protocols. :(