I have been using I pad mini wifi version from past 1 year and my experience has been at its best. It gives you one of the best gaming experiences ever. The touch sensitivity of ipad mini is at its best. The battery backup is also remarkable of that pieceThe size is decent and easily fits in one hand. Easily sync device across wifi with multiple apple devices or with PC. Siri is not just accurate and intelligent but also witty.
No hesitation in providing features to the device the OS updates, apps support etc. Battery almost lasts for 5 days at the rate 2 -3 hr usage per day. A lot of features others are yet to imagine or probably implement in their next release.
Nothing to lose in the non retina model except a slight reduced sharpness which results in lack of sharp defined edges of text, graphic.
A7 chip might not be a big loss for regular usage conditions like reading, browsing