[LaPistola]

It is a nice shot and one to be proud off. I couldn't tell they was riding nor did I notice the old one was hold the younger girl until I read you post. I like the level of blur but can see the PP.

After you explained I can see why and think I know where you can improve.

If you haven't already make your cursor full size. Edit > Preferences > Cursors > Painting Cursors: Full Size Brush Tip.

Now I think the biggest tweak here to your method would be not to reveal the girls but to reveal the blur if that makes sense. Set the blur layer mask to solid black then making sure the mask is selected in the layers panel press (D) to default the colours to Black & White and press (X) until white is your foreground. Press (B) for brush then using the { & } make the brush size quite large. Now the trick here is to have a larger brush size so the feather is wider creating a much nicer blend between the layers. To change the feather amount using keyboard you hold (Shift in windows sorry I know your a mac user) and press either { or } the less "jagged" the outer line the less feather.

If the blur is still a little noticeable or you don't wish it to be to intense you can select the blur layer (not mask) and reduce its opacity. I like to make my blur layers more then required and start by reducing my opacity, this way if it wanted to add more blur then I originally thought, it is less hassle to increase opacity than it is to play with effects again. In fact smart filters would have been a better choose here as its the only PP you required this would have enabled you to just adjust the blur level from the original effect tool which does give you more scope for control.

This is of course if your using CS3 or above which im sure you said your using CS3?