I'm checking it out on my laptop rather than phone for the first time. A couple thoughts.
1. Make it so you can login on the main page. Looks like you have to go to a second page farther down the wormhole of the website to get that option.
2. Boat, italicize your "signature" line. As a regular and somebody that posts a lot, it looks like you're just typing that at the end of every post you make. It needs to look different somehow. Had me really confused when I was on my phone.
3. Offer different color options. I'm certain vBulletin offers some other standard colors. Maybe a grey/white or black/white option?
4. When you actually enter the forums, expand the width of the forum/posts; basically maximize the forum into the whole page so that the background is essentially eliminated. Let's be honest, you guys have some other content on here, but 99% of us are here for the forums. You have to make them as pleasant on the eyes as possible.
5. Personal messages. It's told me for 5 days now that I have 3 messages but it shouldn't. I've seen who responded to my posts, and it's still not clearing. I've seen that function work well, but I think you guys have some kinks there still.
6. Increase the font size of all thread titles. Currently thread titles are the same size font as all other information about the thread, ie who started it, how many likes, when it was started, etc., but as people browse the forum looking for topics, we want to see the titles. Make them stand out more by increasing the size.
7. Have a way to show each user if they've posted already in a thread. EOG does the green arrows which work.
That's all I've got for now. Good luck guys.