I ordered these desert boots especially because they do not have a leather lining inside, it's just the back of suede against your feet, very soft and comfortable. They're more likely a 5 and a 1/2 than a size 5, however a size 4 definitely wouldn't fit me. Just order your size and go from there, I think it's unlikely that you'll have to order a smaller one, unless you're feet are between two sizes, then the smaller size might be better for you.
Very pleased with the delivery, easy to track on the website, and an email and text notification on the day of the delivery. Estimated delivery time is narrowed down to the hour, which is very helpful as you don't have to wait in all day.
Overall I think these shoes are a bargain, they are very good quality for the price. A wider range of colours would be better though! The shoes arrived immaculate, I've almost always had problems with suede shoes arriving marked and sometimes even slightly stained with pen ink or whatever, so I'm very pleased with that.