As for Audiovox, it's important to note that they're not actually a manufacturer. They just brand phones from other manufacturers and handle distribution and marketing in North America.

7000-series Audiovox phones are actually made by Sharp.

8000-series Audiovox phones are actually made by Pantech & Curitel (formerly Hyundai).

9000-series Audiovox phones are actually made by Toshiba.

...so for example, if your old phone is a 9000-series Audiovox, then you shouldn't let your experience with that phone affect your opinion of an Audiovox 8600 - they are actually from different manufacturers.