We have THREE of these phones from Cingular. COmpared it side by side against the Razr.After about 2 weeks of intensive use, we like this phone better than the Razr in everything area except for two things: reception sensitivity and screen size.Pros:Lighter, smaller, slightly more tactile key, and most importantly - more analog sound both in the earpiece and transmitting than the Razr. It simply sounds more natural. Also, having a synthetic body (some kind of plastic) along with its lightweight, should be more durable than the Razr. GREAT talk time compared to the razr etc. Bluetooth with plantronics works just fine. Zero problems there. Finally, the speaker phone is quite usable and noticeably better on both the transmitting and receiving end compared to the Razr. Also, very consistent quality - all three of our phones work identically in reception strength and sound quality. Kudos there.Cons:Razr has better reception. This is a big one. Our home is in the fringe area of reception in the mountains. Decending to the 'basement', we have very very fringe reception. Barely 1 bar at times. Razr takes the call no problem and maintains rock solid connection. The Sony would make the call maybe once out of five times, and then drop it repeatedly after seconds. Basically not usable in this very fringe environment. We continue to drop calls with CIngular often even with 3 bars in different environments. Not sure if it is the phone or Cingular.Also, Razr does have a bigger screen that is just more of a pleasure to see. This is minor for us.Currently, we are keeping the Z520 but the weaker reception than the Razr and dropped calls on all three Z520 is driving us a bit 'nuts'. We have 30 days to decide whether to keep it and are still evaluating.Hope this helps.Addendum after 3 weeks:I would not give it 1 or 2 stars if I could. Called Cingular multiple times to resolve our problems to no avail and received some erroneous information. With all three phones, we would regularly drop calls even with 3 or 4 bars showing. Further, just sitting on our desk, the phone would bounce from 1 to 4 bar and back in seconds. Something is wrong with the internal algorithm. It is possible that the phone is searching for alternate bands? Can't set the band manually. VERY frustrating and poor performance after extensive testing with 3 phones.Final update:We traded all 3 for Razrs and the difference is remarkable. The Razr exhibited NONE of the problems of the Z520 with the many dropped calls. Simply blows the Z520 away. We tried our best to like the Z520 but am very happy with the Razr. Also, we racked up a bunch of unintentional charges with the Z520 as you can push many additional $$ services inadvertantly with just ONE button. THis happened on ALL three Z520s and was very irritating. We never saw this coming until the bill showed up. Cingular charge $20 for games which we never intentionally loaded. They did reverse charges though when we challenged it. In all, one star phone.