Power to the People!
I bought my 2005 AWD 4 cylinder in 2008 with 40k+ miles on it. The original battery was in it when I bought it and it lasted until 2014. When I pulled that sucker out it was heavy, baby. Heavy. As in a whole lotta lead. I thought to myself “I’m never going to be able to get that kind of battery ever again.” I replaced it with a Walmart 24F Ever Start Maxx (which was noticeably lighter) and it’s been good for 4 1/2 years. 3 year warranty so I figure I’m in bonus time. It’s not a sealed battery and I keep it topped up. The charging system is good and the cells all show even charge and I’d be surprised not to get 6 years out of it. I’d be delighted to get 7 years . Ecstatic with 8 years. Deliriously joyful with 9 years. You get the picture. Anyway, as I said, it’s all gravy now.
You ask if there is any advantage to a larger battery. What do you want or need? More electrical power for accessories when the engine is running? (Heavy duty alternator?) Power when then the engine is not running? (Deep cycle auxiliary battery?) Longer battery life? (Heavy/expensive battery.) Any advantage depends on your uses/needs.
All other things being equal, a marginally larger battery will only give you marginally greater benefit, and that’s what what you’ll get with rigging a marginally larger battery tray.
Cheers,
Guylander