I replaced my Gentex K31 with a CIPA 36500. I like the CIPA better. The Gentex had yellowish / greenish non-replaceable LEDs for map lights. The CIPA uses replaceable bulbs for map lights and so I took them out and replaced them with white LEDs:
Another problem I had with the Gentex was that its base stuck out past the dotted area of the windshield. The CIPA's base looks like it was made for the Yaris. Its base goes down 90 degrees just before the end of the dotted area so it's entire base fits within the dotted area:
The Gentex had its compass / temp. display on the mirror, taking up some of the mirror. The CIPA has it below the mirror. Here are other pics. of this CIPA mirror:
The CIPA mirror is as wide as the Gentex (both are wider than the stock mirror) and it's taller than the Gentex so the CIPA is the biggest mirror of the three. It also has the same harness and temperature probe that the Gentex had. Gentex / Mito and CIPA / Magna Donnelly are different companies and I was surprised to find that both mirrors (Gentex K31 and CIPA 36500) use the same harness and temperature probe. The wire pinout of the harnesses are the same as well. Finally, the most important part; the Gentex uses a gel based system for the auto-dimming function while the CIPA uses a completely solid system for the auto-dimming. The CIPA dims and un-dims faster than the Gentex.