Do you count cards?
Ray Palermo,
First of all, in your post you refer to "five-deck Shufflemaster shuffle tables", which I assume is the Shufflemaster Continuous Shuffling Machine (CSM). If the dealer periodically removes the cards from the discard rack and reinserts them into the back of the machine, and withdraws the cards one by one from the front of the machine, then that machine is a CSM. CSM's were designed at least in part to thwart card counting.
If you are not counting cards:
You have a choice. For the same set of rules, the 5D game has a lower house edge per hand than the 6D game. In fact, for equivalent rules, the fewer the number of decks, the lower the house edge. For example, for S17, DOA, DAS, (typical rules here in the South), the house edge for the 5D game is 0.388618414%, while for the 6D game it is 0.409639501% (these numbers come from Eric Farmer's program, available for free from the bjmath site linked below). What these numbers give is the house advantage against a player who plays perfect basic strategy (which Farmer's program also provides) and starts each hand with the same initial bet, or "flat bets". Thus, in either case you are at a disadvantage, since the player's edge is the negative of the house edge, but you're slightly better off in the 5D game (0.02% per hand) than in the 6D game. However, almost always the CSM game will have many, many more hands per hour than does the 6D game, because on the time required for the dealer to hand-shuffle the 6D game.
For example, assume you are flat betting $10 per hand at the 6D game, and it is proceeding at a typical rate of 100 hands per hour. Then you'll be betting ($10/hand)*(100 hands/hour) = $1000 per hour. (Note: the edges quoted above already take into account that you'll actually be putting more than $1000 per hour at risk, due to splits and double downs. The edges are actually based on your initial bet, not your total bet, per hand.) Since the player's advantage (or EV, for Expected Value) is -0.409639501%, on average your result will be ($1000/hour)*(-0.409639501%) = -$4.09 per hour. Now if the 5D game were played at the same rate of 100 hands per hour, a similar calculation will show that you can expect to lose at a rate of -$3.89 per hour. However, with a CSM the dealer doesn't take time to shuffle, so the CSM game typically proceeds at a brisker pace of, say, 120 hands per hour. At this rate, your average result will be given as follows:
($10/hand)*(120 hands/hour)*(-0.388618414%) = -$4.66 per hour
Thus, in this case you'll lose less money per hour (but more per hand) by playing the 6D game.
Of course, if all else is NOT equal, you may be better served playing the CSM. As one example, if the minimum for the 6D game is $10, but the minimum for the CSM is $5, and you flat bet the minimum, your expected hourly return from the 6D game will still be -$4.09, but for the CSM it will be halved, or -$2.33, so here you'll lose less on average with the CSM.
If you are counting cards:
If you want to exercise your card counting skills, then you have to play the 6D shoe... card counting alone will not beat a CSM.
Hope this helps!
Dog Hand