counting edge?

if you use a basic counting strategy like hi-lo, and bet accordingly (i.e. 2 units for true count 2-3, 3 units for 3-4, etc..) what kind of edge (%) are you looking at over the house in the long run?

In a decent 2-deck game, with a reasonable bet spread, you can expect about a 1% overall advantage. In 6 or 8 decks, that drops to about half a percent, and the spreads and risk are much higher.

long term about 1% - 1.5 %.

Remember that in most of six deck shoe game you have to have 1:20 (minimum , maximum bet) spread in order for edge to really pay off. Most of players will disagree because that big spread will bring lots of heat from pit boss, but thats how you have to do it in order to make any money in 6 deck shoe. In single and double deck game 1-2-3-4-5 works just fine. But there is a catch with these games because they have very poor penetration, which means that dealer shuffles very often. Plus very often gets very hot hot hot, lots of heat from casino personnel.

It is very important to realise at the very beggining that card counting is not that profitable any more! It still works, but it takes a lot of efort to make it profitable. At least 90% people that count cards don't make any profit off of it. Some because of not big enough bankroll, some don't have enough time......
All in all it's hard, not so easy as most of books say like 1+1 = 2