Aside from the short length to the starter and service convenience, under the hood is pretty much the worst place you can put the battery. It sees wild temperature swings and a lot of vibration.
My experience with remote batteries has been excellent. My first Lincoln, my LS, went 8 years on the factory battery. It was also always spotless. It gave up on a 5 degree morning, and honestly preemptively changing it had been on my to do list. I changed the battery in the MG last year and the one in it showed an 08 manufacture date. The LS was in the trunk, the MG behind the passenger seat.
As for brands, I’m generally agnostic toward name brands but instead tend toward checking actual manufacturers. Johnson Controls use to be considered top notch, and both Die Hard and Interstate use to use them exclusively(those are the premium name brands I usually think of). JC can be hit or miss now. East Penn is almost universally excellent, and I’ve had poor luck with Exide. NAPA store brand batteries are usually my choice, as they are East Penn in most applications. Auto Zone seems to use Exide for all but their premium. Interestingly enough, depending on where you are located in the country, the $60 Wal-Mart batteries can be made by any of the three-batteries are heavy and it’s usually whichever plant is closest to you to save on shipping. The SN tells you bu the gritstone two letters-EP, JC, or EX. We get JCs in Kentucky, and that’s what’s in my MG and what I replaced.
With that said, all the plants can build batteries to different price points. Thicker plates, in general, make for a more durable battery. Since that’s most of the weight of a battery, the weight of two otherwise comparable flooded lead acid batteries is often a good indicator of quality.