In a way, I think to avoid the criticism, it's almost better to wear "medievalish fantasy" stuff, than to have something that's clearly the wrong period. The "pirate boots" comment is a great example.
But it all depends on what people can see. I often use 15th C. joined hose, even with my 13th/14th kits. But unless you look up into the crotch area, under the surcoat and mail, you're not going to see that they're joined.