from what i've read the punch 75 25 to life is the same as a regular punch 550.2. if you look at the internals i can't tell a difference. sounddomain has them cheap right now though.
I think they are lower in quality than they used to be. I remember a couple years ago there was an article in I think DialD where rockford admited it and was trying to get its company back on track to where they once were. Also I know mtx used to run ads of there amps against rockfords(still a small sample on mtx.com). and the pics showed things like loose solder balls left on the rockford boards and just other things that showed a low quality build.