Tarzan said:
my stating that long term positive results playing against an 8 deck shoe are achieved through selective play and wonging that often involves standing around a lot longer than you would against fewer decks
Actually, you stated only the first part - that you just stand around, "hardly playing a hand". I fully agree with what you stated just now, that you're waiting around longer than a DD or even 4D game. The benefit, of course, is that once you do sit down, you sit down longer than you would in a DD or 4D game.
Nevertheless, the overall point is that because Wongable 6D and 8D games are more plentiful, it's not entirely apparent whether it's better to play an incredible, but unique, game (which will drive up travel costs for most people and limit the total number of hours you play), or whether it's better to play a mediocre, but common, game.
As for what people generally miss about Wonging, my general point is that hands/hr is often ignored in favor of EV. Hands/hr ends up being absolutely crucial in a proper evaluation of Wonging, so it should be treated carefully.
As Automatic Monkey pointed out earlier, Wonging out and jumping to a table with a fresh shuffle requires minimal waiting (if the casino has a lot of similar games), and hand/hr can be as high as any other table.
Wonging in is a little trickier, both in terms of execution and in terms of math. EV increases with the Wong in point, but hands/hr drops pretty fast. There's a bubble in which the optimal Wong-in point is +1 or +2, depending on exact conditions. Most people either don't Wong in (and end up playing a lot of neutral counts) or Wong in really high (which is great for EV, but, as you pointed out, not good on win rate).
Here's an underappreciated point: looking for a TC of +1 isn't that hard at all. As a matter of fact, on a 6D game with 3-4 people at the table, it's pretty easy to see a TC of +1 on the table - the challenge is to find a freshly shuffled shoe so you have decent penetration, not to find a positive TC.
The other point which I think people often miss is that, for optimal win rate, you need to Wong out at a point lower than you Wong in. Otherwise, the time that you spend sitting down and buying in actually ends up being significant compared with the number of hands you play.