I can last maybe 3 - 4 hours on my 2014 MBPr in low power mode at least when writing Scala, longer potentially if it's just Java for some reason. You may also w

I can last maybe 3 - 4 hours on my 2014 MBPr in low power mode at least when writing Scala, longer potentially if it's just Java for some reason. You may also want to try resetting your SMC and see if that helps battery life in general, I know it works for me often enough. As for reliability, I've dropped this same laptop from about 4 feet off the ground on the corner pretty much flattening the rounded edge and it's been fine.