I have a pair of trail running trainers, they are fine in woods, light and grippy on grass and have enough tread to grip in mud and are as soft, light and comfortable as anything else you can wear.
I bought a pair of £40 boots from an outdoor store that are super light. Didn't have any problems at all except obviously can't run as quick in boots. I hate being cold so wouldn't be able to function in some of the minimalist options in this thread unless it was really warm (unlikely in the uk lol)