Make the move before sweat becomes tears LOL.
Motorcraft fluid is good, no question, but it gets used up rather quickly if you drive your car like a performance vehicle. That goes for engine oil, trans fluid, etc. Hence the move up to Amsoil. Hard to say exactly WHAT makes the product better (won't find much useful technical data), but the results (of testing, and from end users) are there. I'd find a BG center and have a professional trans flush done using the Amsoil fluid. That would really give you a fresh start. After that, the drain & fill (if necessary) would keep the fluid all Amsoil. You can do the flush yourself, but I'd spring for the BG service. Signature Series Fuel-Efficient Synthetic Automatic Transmission Fluid is what you want. If you get engine oil, you want the Signature Series there as well.
You buy directly from Amsoil, that's their model. Some dealers DO stock the product locally, although you can save on shipping if you pick up from an Amsoil warehouse. I know there's one in PA, but not sure how far from you.
IMPORTANT INFORMATION ABOUT PICKUP ORDERS
Most in-stock items are available for pickup from an AMSOIL distribution center near you. Please allow at least 2 hours for processing before arrival.
Lancaster, Pennsylvania
AMSOIL INC. Distribution Center
1917 Olde Homestead Lane
Lancaster, PA 17601
Business Hours
Monday 9:00 am - 7:00 pm
Tuesday - Friday 9:00 am - 5:30 pm
Saturday - Sunday: Closed
$10 for a 6 month subscription membership gets you a substantial discount on list prices, which are not shown publicly. You sign up, wait for the packet to arrive with membership materials and number, log into the website and order your products. I think you will like the discounts!