Well, this may help other 425 users or future buyers. Unlike my old 330, you must punch an out mark to make the normal operation of the 3Play work like the 330 did.
Here's my step-by-step procedure. I've discovered through experimentation that while in LIVE mode with A lit, select the camera you want to playback. Then mark an IN and then an OUT. Then, with A still lit, punch CLIP LIST. This puts the play you just marked at the beginning of the play. All you have to do now is hit play at the speed you want the replay to run. If you'd rather change the camera to be played, hold the ALT key and hit NEXT to move to the next camera for the event you just marked. To go back to a different camera, hit Previous.
This is where it gets sticky. If you want to immediately play a different camera (Angle) of the same play...While the play on output A is running you punch the B button. Again punch CLIP LIST and hit NEXT until your on the final event. IF YOU DON"T DO THIS, the event from the last time you played out from B is still selected. Once you hit NEXT until you're on the bottom of the list you're ready to play the camera you select when you need it. The CLIP LIST doesn't automatically follow what's happening on A output. If it DID follow what's on A output, this would be much easier.
In my case, to do a replay, I use a transition which usually highlights my replay sponsor rather than using a simple CUT or DISSOLVE from LIVE to the replay. With my new 425
I'll probably use a cut on my TriCaster between the two staggard camera angles I might be using. The 425 allows for this staggering of the playback of the single play between two angles where my older 330 did not.
When watching instructional videos and reading the manual, they seemed to be talking more about how to use the A and B outputs with PLAY LISTS or a Highlight reel.
I've learned that while A plays the current event, select B and the B CLIP LIST, to get to the current play event. Then go to your keyboard and select alt + Page DOWN (arrow down) and it moves to the last (current) event. Then you can select which angle you want and the point at which you want to replay B.