Performance of an antenna is dependent on not only antenna itself, but also on antenna location, antenna height, length & type of coax connecting it to receiver. Same antenna may perform better or worst if these parameters are changed. For this reason it is hard to judge how good or bad an antenna really is, unless its parameters are measure with costly test equipment.
The DIY situation lacks costly test equipment. The alternative left for hobbyist to evaluate an antenna is by COMPARISON with a reference. There are two easy references available for DIY hobbyists:
Comaparison #1: Determine what maximum possible range can be obtained at a particular location and antenna height, using method described in FIRST POST of thread What is the Maximum Range I can Get?. Obtain maximum range curve of your antenna using VRS, and compare the two maximum range curves.
Comparison #2: Make an easy DIY 1/4 wavelength ground plane antenna (Spider), swap the CoCo by Spider, keeping everything else same (i.e. same same location, height, coax to receiver etc.), and compare results.