If your blunt question is "Does XenForo have all the features of vBulletin 4?" the answer is no. Why? Because vBulletin 4.0 contains a mountain of features developed over 10 years from vB1, vB2, and vB3. No forum software will ever have all those features! But realize that by having a million buttons and options, it's as much a curse as a blessing as the software is so complex and rickety, full of legacy code, that maintaining it is a nightmare. This is why IB is having so much trouble with vB4 and vB5 and part of why it took them 2 years just to get vB4 usable and after 2 years, vB5 is still essentially an early beta.
XenForo is an excellent forum product with a solid, modern foundation which is easier to build upon and will support all manner of modifications. While it does not have 87 million features, I would say it has nearly everything people care about and what was needed most from vB4. And if there is something missing, you can get that in the form of plugins.
People are asking you which features you use because we can recommend plugins and make sure that you have everything you need in your transition.
Also, I'm a bit puzzled why you are considering vB5 as it has less features than vB4 and is a platform in serious jeopardy at this point. It's being developed as a fat AJAX client app loaded up with thousands of lines of Javascript which is a horrible way to develop and which is why it takes 10-15 seconds to click on anything or get any page in vB5 to load. Run away!