Nothing wrong with a fix scope, simple, light, sturdy, nothing to really go wrong! That said I always liked the 2.5-8 for their lightness and how compact they are!
6x always intrigued me in a way that I wonder if they would be too much magnification at close range, like I side 75m ?
You won't have any issues with a 6x at close range. The field of view is quite wide, which helps a lot. There is no struggle to find your target. They are brighter than the 2.5-8 by a wide margin as well, if you go with the 42, and offer better eye relief.
R.