The upgrade options for my 2010 Honda Fit are very minimal and they all require significant modifications... as was the case with this 51R I had installed. I had to cut up the tray due to its larger size than a 151R. Even then, it would sit in there so awkwardly—plus, it was significantly heavier. So when that unit gave out, I did some research and it appears as though this one is the best solution. And yeah, I'm quite stoked how well this turned out. The only thing was that I had to use one of the pieces of packing foam to elevate the battery so that the hold-down would tighten properly.
For the amount of money they charge for these batteries with close to 300 dollars they should have a 5 year worry free warranty. This product is VERY expensive and for the price they pay we customers should get better product support and warranties.