I've been using a Uniden DFR-9 when following ToddC and The Dan.

It helps.
The DFR-9 has some nice features that allow you to customize the alerts and keep from getting inundated by false alarms from grocery store automatic doors and Blind Spot Monitor radars on cars. Like The Dan wrote, you have to understand how the LEOs work. Laser will get you every time. Instant On radar when you're the only one around, will probably get you. But often I've found I can pick up the Instant On radar miles away as the LEO tags other cars.
Initially, I used a BT transmitter to pair up with my BT headset and hear the warnings in my helmet. I still prefer that setup, but I ride often with some riders who have BT headsets and there's only so many things that can be connected on the two available channels. The size of these is about like a small box of matches and easily attaches with velcro to the side of your detector.
I've later moved to the Marc Parnes Visual Alert.
http://www.marcparnes.com/Visual_Alert.htm
That's the Uniden DFR-9 with the Marc Parnes Visual Alert. I'm holding the RAM mount with the magnetic radar detector mount.
The audio warnings are nice as they tell you which band is being sensed. The Visual Alert doesn't differentiate between bands. It's not a big deal. You soon learn what to pay attention to and what to ignore. If you're in traffic and get a warning...look for a Mazda.

If you're pacing the traffic and not leading a pack, you have little to worry about. But if you're going down the road and begin picking up intermittent signals, pay attention. Chances are there's a radar trap ahead. I was going through a small town in Eastern Washington last summer when the K-band was going off. Normally, that's a grocery store but in this case, it didn't quit as I moved. In fact, it kept getting louder and stronger. Eventually, the local Sherriff went by.
I had a humorous situation last summer. I went to WESTOC in Park City, Utah. I needed gas and was heading out of town when I spotted an LEO on the side of the road. I pulled over to ask for his help and my radar detector was going off like crazy. I should've just hit the Mute button but for some reason, I didn't. He laughed as I was trying to get my helmet off so I could hear him with the detector going off.
Chris