EarthX owner, 36 with 405 CCA has started as cold as -20F in an enclosed trailer (spike it when brutally cold, let it sit for a minute, and then she fires). Don't think the 24 would do that. To me, it wouldn't be a big deal to recoil start at the beginning of the day, but I have a high roof trailer. It's real value is weight, and ability to use it many times a day, especially when it's deep. Chem is LiFePO4. Other points:
1. My original 36 failed last year (0 volts) after not being charged in the off season for about 75 days, replaced under warranty with no issues (one of the easiest and nicest warranty replacements I've ever had, FWIW). But it did fail, and it shouldn't have given the their protection features. After one season, the replacement is still working.
2. Get a Li-on specific battery charger. I use the Optimate, put it on every month now. So far, so good. We'll see...