I own several BMWs and have installed the Die Hard AMG cell type in all of them over the last few years. The batteries have had great performance over the winters and summers. The fit is spot on and if there is any issues the warranty covers replacement based on age. On the garage queens I have them on trickle chargers which will extend their lives well over 50% more as it eliminates the drain down and hard deep recharge cycling that kills more batteries than anything else. I would recommend them without any hesitation to one and all.
I just purchased the battery and consider it much too early to provide a meaningful rating. I suggest you check back with me in 2 or 3 years. I purchased it because of the 3 year warranty. So far it has worked well, which is not surprising. To rate it 5 at his point would be inappropriate as would a rating of 1. So 3 is middle of the road.
This battery was a perfect fit for my Dodge Challenger. The engine jumps to life now in a split second. A definite upgrade over stock. This battery also included included everything I needed to hook it up to the existing venting system. Great design and fit. A very well made battery.