I need some advice adjusting my front and rear brakes. I recently had my bike tuned and the pads were replaced. Now when I stop, I don't feel like a get a good solid stop like I did before. I've been riding it for a few weeks since the tune thinking the pads needed braking in.

I checked the toe in and it seems to be fine. I've also tried tightening the cables to get the pads closer to the rims. Could this be a issue with the rims?

The brakes in question are Bridgestone (dia-compe) "SC" series with shimano pads. The rims are matrix semi-aero.

Thanks.