No where else can you find such a value in a cell phone. Quad core processor, removable battery, expandable memory, vivid, big screen, responsive touch, windows office, Microsoft maps, Cortana, OS upgradable now to windows 10. The unit multitasks without stutter, charges in less than an hour, Bluetooth is fast and solid too. Only con for some is limited app store. For those who value a solid phone, with great volume and all the above, for under $30, run and get it now before they are gone. Microsoft is getting out of the phone biz, so I expect this bonanza to end soon. The OS is never sluggish as windows is optimized for mobile unlike android, If you update to win 10, do it first or back up your data to the cloud, I had to reinstall my contacts, and a few pictures. All my apps work with 10 and a new one that didn't with 8.1. The only apps I added are Runtastic, Spotify, Pandora, Duolingo, Waze, OBD car diagnostic, Amazon, and a Password Manager. The camera is sensitive and versatile. The live tiles give breaking news, weather, messages and other data at a glance, apple and android have nothing like it. You could spend $500 on a phone and not enjoy all these features!