I have used several Smiley antennas. I have both 2m and 440 slim ducks. They are supposed to be equivalent to 5/8 wave antennas (use base loading). They custom make them as well as selling standard antennas for ham, commercial etc. Their claim to fame is that they are tuned to work with handhelds (no ground plane). I've been happy with them, but they are not miraculous. One nice thing is that they are modular. When I went to SMA connectors from BNC, I just ordered new base adapters for my existing antennas. I have:
2m slim duck
440 slim duck
2m/220 telescoping (1/4 wave)
220 telescoping 5/8 wave
2m telescoping 5/8 wave (very long to use on a handheld, but good)
California company from the San Diego area.