If we are talking about low limit LIVE cash games then yes!! His books are still basically the "bible" for 1/2nlhe and 1/3nlhe live games.
If you are trying to use them in reference to online 6max then perhaps not. But yes, if you want to just brush up on your fundamental poker skills these two books on cash are about as good as it gets for low-mid stakes poker LIVE. Ie- 1/2 thru 2/5 and maybe even 5/10. The second book focusing mainly on turn and river play starts to get especially deep and some of it will be stuff way above the average 1/2 players head.
If you want to get better and you havent checked them out yet, they are worth their weight in gold.