Today I spent most of the day with a friend building his own instance of Tote. Not only it was great fun, but I also learned a bit about which parts need work (unsurprisingly, tuning and trimming the servos is hard). We also experimented with a slightly different leg geometry (the hip servos rotated by 90°), which gives slightly longer legs with better reach. I think I will make it the default.
One particularly hairy problem we've hit is that his 3.3V Pro Mini is apparently set to 16Mhz for some reason. Fortunately I have programmed Arduinos with the wrong frequency before and recognized the symptoms (the servos got wrong frequency signal), and the board still works with 3.3V (for this AVR this counts as overclocking), but I wonder if it wouldn't cause some problems with more sensitive parts, such as the EEPROM.