I was new to bait casting last year and the last-gen stx (same brake as the SX) served me well.
Many of the people who had problem with them might have set their STX/SX's the way they setup their Daiwa/shimanos - the lure falls relatively free on my luna.
IIRC, the manul on my STX states that one has to set the tension knob that the lure falls about a foot when you flick your rod tip. As long as you set the tension accordingly and with about half of the brake on and it casts just as fine as any other reels down to 1/4oz (of me).
Edwin