With a 5 gallon you are (effectively) limited to an OG of about 1.060 for 5-6 gallon batches. That leaves out alot of the beers that make home brewing fun and worth it in my opinion. No RIS, barleywines, DIPAs and partigyles is no life for me. You can run a very think mash or add some ME but that’s goofy. I went with a 10 gal round cooler when building mine. That said, I f I could go back I would have went with a square cooler since these can be had for much cheaper (free) if you look around and I could have saved that $48 to brew some beers.