I have been using Shorai batteries for about four years in my 650 BMW. It starts the bike amazingly better than the lead acid battery that came in the bike. It is also seven pounds lighter than the stock battery. It also costs about $100 more than the stock battery! That is a lot of money, but it starts the bike so much better it is worth it to me.
You have to be careful not to let these batteries get ran all the way down. According to the Warranty documentation and folks I have talked to if you let them get ran down to almost nothing the chip inside records this and when it is returned for warranty they will not give you another one. I ran my first Shorai battery down to nothing twice. The bike sit for about 6 months and the clock ran it down the first time. I installed a USB outlet that had a LED light that ran the battery down overnight the second time. I had to put a small 2 amp charger on the batteries for a few hours before the battery would work again.
After the first time I purchased the $75 Shorai charger/maintainer. It would not charge the discharged battery after the USB outlet problem, therefore I used the regular old 2 amp charger to get it to a point the Shorai charger/maintainer would work.
Now that I have learned, I make sure the bike is connected to the charger/maintainer on my second Shorai battery. No problems with the second battery at all. No chance of it running down to nothing and blasting the warranty. Shorai says their batteries will stay charged for months, but also says to connect it to their charger/maintainer if the bike is going to sit for more than a few days.
My 2017 700 Grizz starts just fine and the winch works great with the stock battery. I used a Yuasa AGM battery in my old 600 Grizz that I occasionally put a battery tender on it, it lasted for years.
I have had good luck with battery tenders and have several vehicles connected to one right now, even a car! If I had a vehicle that was stored without electricity available, I would take the battery out and put it on a battery tender at home.
After all that, my 2 cents is, Shorai batteries are great when properly cared for, but I am not going to spend the money for one for my Grizzly.