I have owned and do own several Smiley Antennas. Mainly the 5/8 wave slim duck models for 2 meters, 220 and 440. One of the things I like is their modular design with a selection of connectors. I have been able to order new bases for older antennas that originally came with BNC connectors and adapt them to newer radios with SMA's. I have never owned any of their aircraft antennas, but there is one important caveat: They don't cover the entire 118-136MHz band with one antenna. You can order them for different segments of the band. Rubber duck antennas are not as efficient as full size antennas. You might get better results on the air band with a telescoping whip set for the middle of the band. Also, Yeasu and Icom make antennas for their aircraft HT's that might be more broad banded.
The performance of Smiley antennas is good and they are well made. However, as an antenna junkie, I can also say that they are not significantly better than Diamond or Comet for HT use. Also, they are mostly monobanders and I use them on monoband HT's.