Hubby and I have been to two local ones, years ago, out of curiosity, we do not show or breed and run a small guinea rescue in the UK.
I personally, wouldn't want to be involved in anything like that. The guineas spent long periods of time in very small pens in close proximity to each other, I am very strict about the quarantine of rescue piggies and so would not condone penning like that for a start.
As I remember many of the pigs were very relaxed on handling and well used to it, but quite a few, poor little things were terrrified and looked very stressed. Just my opninion....not my idea of fun...or I'd say a guinea pigs.
Wouldn't visit a show again...unless to check on the welfare aspect.