I have been using 2.4 Ghz since the first Spektrum DX3 surface radio went on sale. I still use my DX3 and love it. I also have a DX7 for my flying and love it as well. They are very nice radios with easy programming, short antennae, few frequency conflicts, and the ability to fly/drive multiple models without the hassle of crystals or synthesized technology.

On the downside, I have had more issues with bad Rx's out of the box than with AM or FM band radios, as well as being more sensitive to mounting location on an environmental (heat, fuel, etc...) standpoint. A good example of this just happened to me. I bought a new Hangar 9 P-51 PTS "RTF" to start my RC fixed wing training with. I wanted to use the DX7 that I have been using with my electric helicopters with great success, so I bought an AR7000 Rx to take the place of the 72 MHz FM RX that comes in the plane. I swapped out the Rx's and charged the battery overnight. When I got up this morning to bind the Rx to the Tx, the bind light on the Rx would only flash once and go out, causing me to not be able to bind the Rx to the Tx. To eliminate the possibility of a dead/bad battery, I swapped back in the FM Rx. Everything worked great, and I was able to run up the airplane and taxi it around for a full tank of fuel without further radio issue.

I also agree with King, no radio transmission is immune to interference. I can speak from experience. Racing an electric 1/10th scale on-road sedan with my 1st generation DX3 surface radio, I had many times where I would experience radio lockout on the backstretch of the track, which was no more than 50-75 feet from the drivers stand.

That being said, I still enjoy using my 2.4 radios and have had many Rx's that have never given me an issue. 2.4 GHz is still a new technology that has not been fully adopted as the standard as AM/FM bands have, and it still has some bugs to be worked out. Now that the 3 major radio manufacturers (Airtronics, Futaba, and JR), some of their divisions, and other newer companies have 2.4 GHz systems, the technology should begin seeing massive improvements IMHO. All of this is just my opinion taken from my personal experience, and may not represent the opinions of others, or the overall RC community.