I'm a new convert to fat tires. After decades of 25s, then maybe 5+ year s of 28s on some bikes, I now have 38s on new gravel bike. I can't tell the difference speed/effort wise, but the comfort on crappy urban roads and MUPs with uneven transitions is night and day. Also loving the 1x. 11 cogs with a 40 is way more than enough for me in the area I live. Finally embracing reality over fantasy (my abilities, needs), may lose the drop bars next.