Never heard of Power Towing brand tires. Did you mean Power King Towmaster tires? I bought a set for my TT a few months ago. So far, so good. I wanted size ST215/75R14 to replace the slightly smaller ST205/75R14 tires on my TT, and Power King Towmaster STR trailer tires had a good reputation, so that's what I bought.
Power King Towmax STR Tires | The New Standard in Premium Trailer Tires
However, the Landgrube website shows Karrier tires (by Kendra) on their tow dolly.
Landgrebe Mfg. Inc.
Grumpy ole man with over 50 years towing experience. Now my heaviest trailer is a 7,000-pound enclosed cargo trailer, RV is a 5,600 pound Skyline Nomad Joey 196S, and my tow vehicle is a 2012 F-150 EcoBoost SuperCrew.