I’ve been to IOW 3 times and the only reason we don’t still go is the cost of taking a motorhome. We had 3 great years.
however IOW is not a Glastonbury alternative, it’s about as far from Glastonbury as you can get.
it’s more of a sit in front of the main stage all day watching pop music type of festival. There is the big top which is basically the JP tent and a couple of smaller stages with people Ive never heard of but others will have.
there is almost nothing else to do, a few shops, a fun fair( which is far too loud and too close to the stages) and that’s it.
its very family friendly, a nice atmosphere and I’ve never queued more than 2-3 minutes for a drink. It’s a long walk from the camping to the arena and the last year we went they are very hot on searching for alcohol smuggling.
I’ve never seen any trouble and generally they have good weather.
the toilets in the arena are really good, and the food is general festival stuff, not Glastonbury levels, but better than just burgers and pizza.
We now go to latitude instead, but that’s a very different festival.