All the available data says that the drag is the same for both reels, and that the SX weighs 8.7oz while the STX weighs 8.75oz. According to what I have read the only difference between the two is that the STX has a coating on the pinion shaft to reduce friction. Having handled both I was the most impressed with the SX, however I found the Revo SC which is the same as an SX with only 9 bearing on sale at Cabelas last September. Normally priced $129.00 on sale for $79.00 plus a rebate of $10.00 from ABU Garcia. Bought 3 and love them. If they come out with the SX in 5.1:1 this fall I will buy one.