The DB4 was the strongest antenna I have tried. It is also the only one that receives every digital station at nearly 40 miles from the Kansas City stations, (and my signal meter pegged.) I was even able to pick up a few out of area stations I was not expecting. The build quality is better than anything else I have seen.
I have recommended the DB4 to several friends who are also having similar success. It would be hard to screw up HD reception with a DB4, but I would not use an antenna as strong is this if you live less than 5 miles from the transmitters as you may encounter multipath interference.
Also keep in mind, even a great antenna can not make up for line of sight obstacles such as buildings and hills, and no antenna will it solve installation errors with, poor connections, splitters, long cable runs, low elevation or faulty tuners.