Montego classic cat food

I was very sceptical trying Montego Classic for my cat ( as I read some negative reviews) but I ended up with 5 cats and buying Royal Canin and Hills just became too expensive. In the 1st week I noticed one of my cats had 1 episode of diarrhoea and 1 of them had 3 episodes of vomiting, after that it settled. I've been using it for a month now, now more issues. They're loving it, their coats and weight remains healthy and it's affordable to me.