Spongy pedal? Sorry to disagree, but my pedal travel is about an inch and rock hard. It's important to match the piston volume with the master cylinder volume, otherwise the master might not move enough fluid for the selected calipers. Also I haven't found that a lack of dust seals adversely affects performance or longevity. The current line of Wilwood calipers have stainless pistons so corrosion isn't really an issue. If your really concerned, you could clean them a few times a month... Additionally, the Wilwoods I'm using are forged, and certainly stiffer than any factory caliper I've seen... Well, that's just been my experience..