I haven't used that particular model, but the Azden UDR line in general is a pretty good value for the money. I have the UDR-500 and like it, though the RX is too large to mount on a small handheld cam.
The UDR-200 is a dual channel system, so you can receive signals from two microphone transmitters at once, and record one to the left channel and the other to the right channel.
What you give up is a diversity receiver. Instead of each RX antenna receiving the SAME signal, and the unit deciding which is the strongest and clearest, each antenna receives a DIFFERENT signal. This increases the chances somewhat of getting an RF dropout. However, the convenience of having two mics in use at the same time may outweigh this.
As with any wireless, check the operating frequency range against other UHF users in your local area. Digital television stations, especially, are providing increased sources of UHF interference in metropolitan areas.