Me? I didn't really "need" a 3v system, but I made a ton of 11 gallon batches with the all-electric HERMS with a tippy dump. It was great for the time, as I could easily program the control panel to heat 13 gallons of water to 160 for me, hold a 25 pound or more grainbill mash to within a degree, batch or continous sparge to the BK (or no sparge if I wanted), and then boil 12 gallons, while I used the tippy dump to dump my grain, all in the comfort of my heated laundry room. The CFC and HLT stirrer really were nice, and I did continous recirculation. I made award winning beers with that system, and it always was dependable and repeatable without any issues.
I have always brewed indoors, and the 3 v large system was all-electric, dependable, and large enough for 11 gallon batches. It worked for me for a really long time. I think I had it about about 12 years and it was well-used. But now I'm older, drink less, brew less volume (only 5 gallon batches mostly now), and want some of my laundry room space back. I've been brewing for more than 20 years. All of it has been right for me at the time, from the cooler and bucket in 2004 to the Brewzilla in 2024. Maybe......I'm not really that thrilled with the all-in-one's limitations. But for now, it will do.