I love these brakes, the back brake is amazing... I feel like I could stop a car with it. I'm having some issues with front however, I believe it's the caliper but thats why i'm hear asking =P

So I took my bike to one of the LBS around here because I couldn't get my front to bleed and feel how i wanted it, always felt too stiff, too pressurized. well, they rebled it, felt pretty nice, softer to the pull, a bit better on braking, but over the last couple weeks it's felt like it is filling up again and getting more and more stiff. could the caliper be sucking in air and making it so it feels rigid like it is? I have another caliper and i do have a piston/caliper rebuild kit so i could have a caliper with fresh internals on if i went that route, but before i start dismantling i wanted to see if anyone had any other ideas? I cannot for the life of me get the front tire to lock up. i know you dont want it to lock up while riding obviously, but if i have it in the garage, holding down the front brakes and putting pressure on the bike i can inch it forward ... the brakes not holding. the rear the tire will lock right up and just drag until i release it. any ideas?

thanks so much, so glad i found this forum filled with smart folk!