I am rather 'small' down there and often find difficulty taking some toys if I'm not warmed up first. I find it difficult to take my man when I'm not warmed up first either, can be uncomfortable and sometimes even painful!
Although, I have the Doc Johnson Ballsy dildo and when I took it out the packaging I thought there would be no way I could take it, but with the right amount of lube and feeling very horny, I can take the first few inches and feels really good! Can't take any more than that though,