A buddy of mine has both of these balls and is a down and in player.  His comfort zone s playing the track area, with moderate speed.

Both balls are drilled very similar (pin just right of ring finger)  The Defiant is a pretty early ball for him and the Edge compliments that well when they start to transition.  He's been on a tear this week using the Edge exclusively going 750 750. 

If our center was a little heavier on the pattern they would be a great 1-2 punch for him. 

I am a "whatever the condition calls for" bowler. I can shoot down and in, shoot a swing, or throw the big wheel. Anyway, I tested my new Defiant Edge today on a third game, THS and ended up playing up the boards with it. The ball is an absolute beast! I would also recommend this ball, more for a THS, rather than the Defiant solid. With the right drilling you could play a normal down and in shot with it, probably a pin down drilling with the MB swung out slightly.

I have the Defiant Solid, drilled pin down.   It's worked really well for me with the heavier volume on the 43 ft pattern.  I've been able to play up the boards or swing it and have had no problems with it.   It's also worked really well on the slicker Brunswick Anvilane synthethics at another house I sub at.

As of late, I've been using either my Rogue Cell, Infinite Theory or Outlaw since the volume isn't as heavy as it had been earlier in the season.  Then again, the league shot was messed up since the new ownership actually cleaned out the lane machine.  The old owners decided to never do that, so it made for a really weird wall shot that was never consistent.