i think it's going to be quite succesfull if the device's footprint is very small for a five incher and if lg decides to skip the ubiquitous and awful (for the g3 mini) snapdragon 400 and use a more powerful soc instead (or the s400 clocked at 1.6ghz at least).
Useless, like s5 mini. My s3 mini has hardly less processing power and much nicer size.
4x A7 is not really any better then 2x A9. S4 mini with 2x krait is much better then competition.