You have it right about the reason aces are good, but I forget why 5s in particular are bad, which is interesting. Someone know?
The way I understand the ace-five count is that it is a weak way to determine when you've got a better chance to get an ace. Once you get a good count you gotta get lucky that one of those aces lands on you with the hope that a plethera of tens comes behind it. Does it increase the effectiveness of the count then to be playing mano-a-mano against the dealer? With a full table there seems like a lot more places those cards rich in aces could go.
The overall odds are the same. The main purpose of counting is to know when to get the money on the table. You shouldn't be identified as a counter which gives you an advantage at a full table. You'll probably be able to wong out in place. Just give a ploppy excuse as needed.
It's nice to see you take a break from the religious threads. If you decide to get serious about blackjack we can explore other counting options.