There are few quality dual sim mobiles on the market, I wanted one I could put my work sim and personal sim into to save having to carry 2 phones.
Plus points of this phone are 2 sims active at at the same time, fair battery life (3-4 days average), good touch screen functionality, excellent call quality, good signal, reasonable camera and very bright flash, memory card slot, good size colour screen.
Minus points, no 3G/wifi/GPS, limited apps, touch screen can be awkward at times, no match for an Iphone or smart phone.
Having had the phone about a month, no real problems, you have the choice of which sim to use when texting or making calls, you can turn off either or both sims or even set them to be on and off at certain times automatically. Have used to make/receive calls, text message, and basic mobile internet, no problems with crashes or getting stuck. Overall this is a reliable functional mobile, I used to use a Nokia N95 and the B5722 is way more basic in many ways but for the price it still does a lot and being able to have 2 sims on different networks in one mobile is a really neat idea. If you really want an Iphone get one, you'll be disappointed with this Samsung, if you just want a reasonable dual sim mobile the Samsung B5722 is a good choice.