I talk on the phone all day at work, 7.5 to 8 hours, and I wanted a wireless headset for a long time. My coworker has been using the Savi W440 version of this product for the last 5 years and loves it, so based on her satisfaction with it and its longevity I decided to go with Plantronics. I chose this one because it comes with a second battery that you can swap out mid call if you need to. I considered the Savi W745 with the spare battery but since we use an Avaya soft phone system at work there is no handset on my desk to tie it into, I don’t need any kind of a lifter, and just don’t want to tie it into my cell phone at work, I chose this one instead.To set it up I first plugged the usb piece into one of my computer’s USB ports, it downloaded the software it needed to my computer on its own without any action from me. Then I opened my Avaya and went into its advanced settings and changed both the speaker and microphone to the Plantronics device, closed and reopened Avaya, and I was all set. There is a little slide switch on the back of the battery to turn it on/off and then I need to press the side button on the headset to go live for calls. I test it by selecting the voicemail system we have so I make sure I can hear when a call comes in. It states to give it a minimum 3 hour charge before use, but I set it up and let it charge a full 24 hours before first use. I leave it charging during breaks and lunch, and of course leave it charging overnight. I have had no issues with one battery running out whatsoever during an 8 hour shift, so to make sure I don't wear out the batteries by either non-use or overuse I just swap between the 2 batteries every week. My friend told me she has purchased a new battery about 12 to 18 months, only time will tell how often I’ll need to replace mine.I was initially concerned about call clarity having just one speaker on one ear, but I hear very surprisingly well with this on. It has the odd effect of making me feel like I can hear callers through both ears, even though it's only on one side and I found I had to turn the volume down so it doesn't blast my ear. I wound up using the simple ear hook (as pictured in the main picture) and ear bud, but I had to move it to my left ear, my right ear was too sensitive to sound and I got a blister on my right ear when I used it there, while I have had absolutely no issues using it on the left ear. Weird, but my friend also said she went through an adjustment period like that when she first got hers too.I love that it gives me the freedom to move around instead of feeling like a dog on a tether. The range is awesome. Our office is extremely wide and I never lose a call or call quality when I need to wander a bit. I've seen other people run off to the break room (otherwise know as the 1,000 yard dash) or even bathroom and not lose their calls, but that is a bit too much wandering for me. Also I don't want to be the person sitting on the toilet taking a call. (ewwww) And while I hate to admit to vanity, I love that it doesn't give me "headset hair" which I always hated. All in all I love it. It works exactly as expected and needed and I feel much more comfortable and relaxed at work I recommend it to anyone who needs a wireless headset for calls.