"Should I buy this?" - I know my answer will be pointless but it's simply: It depends.
This headset does not have better quality sound. The sound you hear is of very poor quality from the start and no headset will clear this up. People who claim the sound quality is better is simply hearing it because they want to hear it.
My biggest problem with the headset is it's very uncomfortable, at least on my ear. After wearing it for about 3 hours I couldn't really feel it any more as long as I didn't move my head - however, once I finished my gaming session and took it off I realised why. I had basically lost the feeling in my ear due to the way it put pressure on my ear. It might fit better on some people but the problem is you just won't know until you try it on yourself.
As for battery life. As long as you let the headset charge its full 6-7 hours BEFORE you use it the first time and then let it fully deplete and fully recharge a couple of times, you should be able to maintain a healthy battery and get many hours out of it. As for the reviewer complaining he had to recharge it every 2-3 days... what do you expect? There's no portable nuclear power plant built in to it but a tiny battery... hard to believe, I know.
To sum it up, don't expect miracles out of this headset. It won't revolutionize your Xbox Live communication and it might not fit your ear very well... and you will have to recharge it every other day. So if the cable on the original headset is a nuisance and too intrusive for you then this product might be what you are after. My advice is to try it on first if you have a chance, it's certainly not for everyone.