Has anyone had any experience of these? We are looking to get me one for work for when I'm working in places a long way from normal 4x4 access, but although I see them for sale online, I'm interested to know how well protected the rifle and the sights in particular would be from vibration/bumps. Also some of the ones I've seen look as if all the weight is on one smallish bracket. A lot of stuff that is absolutely fine for recreational shooters or one or two days use a week doesn't stand up to every day use I've found. Has anyone any experience of using one?