The R-3 is a nice unit, but be warned...It is a MASSIVE battery hog. With that LCD on, you're looking at an hour tops (my experience) of continual use. Turn it off, and it jumps to around 25 hours.
If you choose to get one, my best advice is to get the Radio Shack 1.2a multiple voltage cigarette plug, a "B" adapt-a-plug, and a 6v 1.8a wall charger. These will allow you to use the unit, charge the batteries, and still be able to use it for an extended period of time. You'll have to strap on an RF choke too...My R-3 seems to absorb interference when plugged in. I recommend the cigarette plug personally. With this one, you can use it for other devices without buying a ton of adapters.
If you have any questions about the R-3, shoot me an e-mail:
GTChrisB@hotmail.com.
I wrote the review on the R-3 in the review section of this site. Check it out, hopefully that'll answer some questions.