here's a good read
i'd say most all mobile antennas work pretty much the same as far as gain is concerned. But different wave lengths give you different angles of radiation. For close range trail work this can be critical. I prefer 5/8 wave. The shorter 1/4 wave dual banders can really make your rig a short range wonder. This is great if you have lots of different trail groups close together on the same frequency but not so good in an emergency situation.