I had buyer's remorse on my SS hoses - but they were installed very early after i bought the car so, they essentially replaced new rubber hoses that had no age or tendency to 'balloon'. I detected no difference after they were installed. perhaps they will last longer though.
the best upgrades on my wrx were stickier tires and StopTech Street performance pads, in that order. You can spend more money for pads, but the ST SP pads are an awesome value for their performance. higher MOT than Hawk. there's a huge thread at NASIOC on them, you could search that thread for other brands and see if anyone has switched/compared. Ferodo DS2500 are well respected pads but $$$
I would probably get Centric Premium rotors but, there are options there as well. Actually, OEM parts aren't bad - just pricey.
Some people say a master cylinder brace helps with the 'mushy' feeling - I have no experience with that.
there are many options for upgrading brakes, but much of the utility of doing that is lost if you don't run better tires.
nowadays, slotted and particularly drilled rotors are probably a waste of money except perhaps for a dedicated track vehicle. Modern pad compounds just don't outgas as much as in the past.
expect more brake dust with upgraded pads.
you might look around at
http://www.knsbrakes.com/ and at
www.boxer4racing.com for some ideas