That 6-5 payoff means that every 20 hands or so you lose 0.3 units which means every 100 hands you lose 1.5 units, so that's a 1.5% disadvantage right there. In blackjack, that's HUGE.
You need a true count of +4 just to be even with the house. That will happen about 20% of the time on the second deal, and of course never on the first. That means that one out of 10 deals you will have an advantage of on average 1% and 9 out of 10 times you will have a disadvantage of on average 2%. You therefore need a 20-1 betting spread to break even, if you play every hand, and that assumes perfect playing strategy.
This is of course not an exact calculation, just a back-of-the-envelope estimate.
Conclusion: don't expect to make money playing this game. Play it for fun like any other game, but don't be fooled into thinking you can beat it.