your opinions please ?

All depends on the level of the engine. If it's an honest 650+hp, long stroke that will be revved, or higher static ratio, they work great. But not everyone can install them really well. If your shop hasnt done them, tell them to be careful, or have someone else do that operation. If it's messed up, it really makes a mess. They are not really much stronger, but they will tend to ease the stress on an RB main webbing if you're really pushing the envelope.