There is a difference between the Xbi and the Xbi2, the main one being that the Xbi2 allows for bike to bike communication up to 500 meters and is waterproof. I've had the Xbi2 for about 45 days. I installed it in the Shark Evoline. The install time took about 7mins. There are videos avail on YouTube. Just look for Xbi. The Xbi2 also provides sound in stereo. Phone paring took about 1-2 mins and worked flawlessly. The sound is very rich for such small and thin speakers. I have them installed under some helmet padding, so they would probably sound even better closed to the ear. I installed under the padding simply because it was so clean. I have my mp3 player connected via audio wire and sound are clear up to about 70 mph. Clarity depends on amout of wind the helmet is exposed to. The controls can be operated with a glove, but take a liitle time to learn where the buttons are. I simply connect everything, turn unit on, adjust volume, etc before I even put helmet on. Volume has to be adjusted everytime unit is turned off. I have gone 5 hrs listening to music continously without charge. Two units take about 1 min to pair and work as advertised. I've operated unit in downpour and had no problems. I know chatterbox has had issues with quality before. They seem to have a winner here. I purchased mine for 179.00 retail is 229.00. Cyclegear has them in stock. Packaging is very similar to Xbi so be careful when you purchase. There is a full face and open face version. ******note****** Xbi2 does NOT stream stereo to both units so passenger can hear, the Xbi does. With Xbi2, passenger needs their own source of music. The battery is replaceable with both units and should last about 8-10hrs on a charge.