From all that I've seen electricity lines (also HVDC) have higher transmission losses by a magnitude. With hydrogen and modern material science you'll probably have the choice between higher losses and embrittlement, but that's just another economical equation: Do you want to eat the higher losses, or replace the pipeline in a couple of decades or a century.

At least environment-wise hydrogen leaks aren't an issue: Some atoms diffusing through the wall don't constitute a fire hazard and the end result is water. Methane, OTOH, is a nasty greenhouse gas.

Speaking of nature: Ammonia is nasty, but nature produces it itself (just not at those concentrations) and can deal with it. The site directly surrounding a leak would be dead, a bit further downstream (literally) there's going to be over-fertilisation. Not nice but definitely better than an oil leak and fixing it quite literally involves waiting until grass has grown over it as rain dilutes it and microorganisms migrate back in to eat it. Similar things apply to ethanol which I'd say would be a better choice for general use such as hybrid cars, camping stoves and whatnot because it's not going to burn your lungs away. Can't rely on people being conscious enough to get up and flee the ammonia stench when they're in a car accident.