Both are multiband, 3 element max yagis. Both use traps (ma5b also uses capacitive hats) Both have almost same declared gain TH3JRS is much cheaper ($150 less), but also has no WARC coverage. Also, it appears to have wider coverage on 20 meters. MA5B is lighter, and does not requires specific shipping options as TH3JRS, but it is more expensive, with only 150khz bandwidth on 20 meters If it was you, which one you'd choose and why? Used power won't exceed 300W, so both fit in power limitations.