75N is not fun. Fort Worth is really a terrific place to visit for many reasons. People in the area are often "More Dallas" or "More Fort Worth"--with exceptions of course. FW is the Stockyards, and the whole "western" idea (Here's a decent link with an overview for that: https://www.fortworth.com/things-to-...rn-experience/ ) I should add, Fort Worth's Kimbell Museum is really great, if you like museums. Depending on what's there, sometimes they surprise me.

Dallas is a typical "big city" in many ways, which is not to say it doesn't have its own culture. The West End is lots of fun and unique. Dealy Plaza (JFK assassination) and the Sixth Floor Museum are in that area. There is plenty to do on that side of the Metroplex too.

Dallas and Fort Worth are about 40 miles apart (maybe 30, depending on how you drive). Doing both is unrealistic if you want to enjoy the visit. Which one to do depends on preference. Terrific hotels in both also. A friend recommends the Hotel Drover in FW (Marriott), but I have not been, so cannot confirm. Downtown Dallas has many nice ones, though check reviews, or ask here.

75N is also North Central Expressway, and people are stupid crazy on that road. I can tell you which windshields I have lost there, which dings have come from that highway, and if it's raining, heaven help you. Dallas and north Texas forgets what water is (anyone reading this, don't come at me. Most of my adult life was spent there. I am speaking from experience.) Based on your signature line, you know how to handle yourself in cities, so you can navigate fine. Just watch the time you leave from wherever, and while toll roads and opt ins on rentals are the worst rip offs, in this case, take them if you are having to dodge across from FW to get to 75, then you want to use the Sam Rayburn (121) toll, which is not cheap, but is probably the most helpful toll around. Unless it's been implemented in the past couple months, Dallas does not have anything like IL or FL where we can buy our own pay-in-advance, so it's the rental car option or no tolls (from what I can gather--I would love to be wrong on that because I still commute to work in the area, but my car is in the Midwest with me. I have taken to Ubering to my office and not bothering with a car rental; cost is similar.)

Finally, take whatever interests you have--history, arts and culture, theatre, etc., and see what fits you best that day/night. I'd use that to choose which to visit. Fort Worth may be the best for a different vibe, unique experience. Stockyards, steak dinner (probably in the Stockyards from a locally supplied cattle company, etc. (many of the most recommended--not all--local steakhouses are in this article. I am linking it just to give you some ideas, not because I think it is a perfect representation). Bypass the city on 121 and head to 75 that way. Get around McKinney before 1 or 2 PM if you can. There is ongoing construction in the Sherman, TX area. Depending on what they are doing this week, it can be a new level of pain. The road narrows, the semis narrow in front and behind you. Watch for those pebbles. Just take the insurance--credit card primary or whatever you use. Just in case. Every day many windshields die on 75. *May the driving gods have mercy on their glass souls*