Good responses and the common theme is...yes, highly variable. I've found that there is slightly higher ability to accept more girth from women who have had children BUT this is only through my own experiences when younger. I think that anywhere between 6"-7" is a fairly safe length guide for what most women are comfortable with. Many women experience discomfort or pain if you are reaching the cervical entrance so that it generally to be avoided. I have heard anectdotle evidence of some women who enjoy the sensation but really can't comment on it.

I've had some women who struggled to take my penis length of about 6.75" and I have not achieved full insertion on those occasions. However, these instances tend to have been fairly isolated. I don't have above average girth but have found that in every instance, as we know from experience, initial penetration for the lady isn't pleasant if there isn't sufficient lubrication.

On a first encounter, always lots of foreplay until it is clear that she wants you to enter. Always go in slowly (unless she jumps on you and has a vigorous plan in mind!) and you will soon find what is comfortable in that particular situation.

Just my 2 cents.