Difference between mph 2.5 heads and the stage 3 heads?

[Cobra123089]

Pretty much what the title says, I just want to know the pros and cons to each setup, Which ever one i choose i will also be doing comp billet cams if that makes a difference. TIA

 

[san~man]

For one, stg 3 can only be installed by them. They won't drop ship or sell OTD.

 

[RoadconeTuning]

For one, stg 3 can only be installed by them. They won't drop ship or sell OTD.

that seems somewhat stupid.