Wolfe, if you were going to go to Download and have issues, look into the disabled access. I qualify for this and had a carer with me and the carer went free. On the viewing platform there's a lot more space than if you're on the main field.
If at gigs, be careful re the toilets as there's usually a large queue, especially between acts. I would love to go to Stonesour in Cardiff in December, but due to events in Manchester, not sure if I'll be allowed to go.