Aref isn't needed here and I can safely skip it. The chip is running 100% digital, no analog reading. B variant has only 2 VCC pins, not 3 like the older versions. Also I am running off internal oscillator so no need for external clock.
AVCC is the supply voltage pin for the A/D Converter, PC3:0, and ADC7:6. It should be externally connected to VCC, even if the ADC is not used. If the ADC is used, it should be connected to VCC through a low-pass filter.
Note that PC6...4 use digital supply voltage, VCC.
analog A6 and A7 are full GPIO and not analog only input like on other 328s. On other 328s, those 2 pins are multiplexed through other analog pins and internally is wired for input only.
2 more GPIO from pin 3 and 6 as D23 and D24
a bit cheaper than non B variant.
26 total GPIO pins by using internal oscillator (27 if you disable reset pin but you'd need HV programming to change code or restore reset), 8 analog inputs, and 10 PWM pins. The only drawback is this do not come in PDIP form at all. PDIP would lose a few pins anyway, having 6 total pins fewer than TQFP and VFQFN, unless Microchip goes with 32 pin PDIP
(It seems quote tags and other tags need to be on their one separate line to work - Moderator)
Not an issue if I'm not using it to directly drive bunch of blinking LEDs. Most of what I use is control other chips or functions and generally chip to chip communication is in the micro-amp range.