Thanks for your reply Latexxxlover. It's always good to get user people's advice/experience on potential purchases. I guess we've all got a few items in our toy collection that didn't quite work out as expected when viewed online.
I was definitely planning to buy a relatively small one (which as you suggest, would be more like a medium plug). I'm not too worried about the size (given other items in my collection) - but I do want this one to be comfortable for wearing for a reasonable amount of time. I like the idea of the vulnerability of being 'open' to teasing with other toys/items, fingers or liquid
I'm guessing this is the right place to post for this sort of advice. I've got another request about canes - but will start a new thread