There's still a weight difference in most cases. I can't speak to all monorails, but I have a Cambo 4x5 that weighs around 9 pounds without a lens or holders. It takes a sturdier tripod to hold it since it isn't as centered as my smaller cameras. I've been eyeing the Chamonix and Shen Hao folding 4x5s and they weigh around 4 pounds. I have taken my 4x5 into the woods, but not that far and not to some places that I'd really like to shoot 4x5. If you want to just try out the format, monorails are usually cheaper.