This review of antennas has both misinformation and omitted information.
First, there is no such thing as an HDTV antenna. Antennas are designed for the frequencies and polarity of the transmissions they need to cover. The antenna is agnostic. It responds to analog and digital transmissions and care less whether or not the signal is 480, 720 or 1080. And by the way, there are no 1080P over the air transmissions in this country.
Some locations that have strong multi path reflections (city buildings, mountainous regions) will require an outdoor antenna, with a yagi being the preferred design as simple dipole or dipole with reflectors have a broad beam width and will reject unwanted signals/reflections more poorly than a yagi design