I've read some mixed reviews on the Mon-3. First, it's been out of stock at dealers for almost a year so restarting production may or may not be true. It's pretty expensive for what you get although it is apparently well made. The radials are 38 inches, which is considerably larger than the 20-176. Users who have compared to Mon-3 to the 20-176 say it's better at 800 and, for some reason, low band, but not as good on VHF or UHF. I guess it all depends on what you listen to most. If it's VHF or UHF, I don't think you're going to find a much bettter antenna than the 20-176. I'd consider putting the money into some good coax first since you need that anyway and see if the 20-176 really needs replacement.