I used one of the velcro-on MicroVoxes for a while, and it worked pretty well, though the wobbliness was a little concerning. But the first time I used an accordion with internal mics (my Tyrolean III came with MusiTek micrphones installed), I gave the MicroVox away and installed internal microphones in every accordion that I use for amplified performances. It's that much of an improvement. I tend to alternate between playing piano and playing accordion, so I put the instrument down and pick it up a lot. Probably my best buy was a
coiled Vox instrument mic cable... so that if I pick up the accordion while accidentally standing on the cable, it doesn't get pulled out!