I took the O+ 8.15 out for a spin for a couple of weeks; and now, I've got the results you might need, especially if you're planning to buy a quad-core phone with a lean budget.
Teased last month by O+, the 8.15 comes with a Quad Core processor, 8MP rear facing camera, 1GB ram and 5" IPS display. Oh, I just cannot wait to get my hands on this device.