I can tell you that I have the Asus Prime B350-Plus with the latest 0805 Bios with AGESA 22.214.171.124a and it runs great with a Ryzen 7 or Ryzen 5 CPU. Here's a comparison of the two. Both are good mainboards and the B350 chipset is stable and reliable with the AGESA 126.96.36.199a updated bios. Check the ASUS site for the mainboards latest bios and any other technical information needed to make an informed purchase decision.
Asus Prime B350-Plus: PRIME B350-PLUS | Motherboards | ASUS US
ROG STRIX B350-F Gaming:ROG STRIX B350-F GAMING | Motherboards | ASUS USA
Outside of chip set difference there are a few. VRM's; the Strix has 8 and the Prime has 6. The amount of VRM's can help with overclocking.
-The Strix comes with ROG software. (CPU-Z,ROG RAMCache II, ROG CPU-Z, ROG CloneDrive, Overwolf)
-5-Way Optimization by Dual Intelligent Processors 5, this allows the user to use the Asus auto tuning, TurboV, GPU Boost in the AI suite.(Nice for overclocking)
-ROG SupremeFX High Definition Audio CODEC S1220A
- Aura Lighting Control
- And most important to me a full Q-design, Q dimms slots, PCI, I/O shield
-The Asus Prime comes with no software (you can download it from the Strix support page).
-missing the 5-way optimization Dual Intelligent Processors 5
-Realtek ALC887-VD2 (older)
-No Aura lighting
- Q dimms slots and 1 PCI slot.
You can find this info on the product pages for each one but if you are unfamiliar with Asus motherboards you might miss these Asus only features.