Which Pointe are you looking at?
Mack and Vernier is GPW on both sides of Mack.
Detroit only extends north of Moross for about a block on the west side of Mack after that it is GPW.
The Detroit side of Mack between Cadieux and E. Warren is an area that has never had great property value. Mostly small cheap frame houses. In the past crime was not a huge problem in that area (I owned several houses there and knew people that lived there). I think it has gotten worse but still not as bad as further west on Mack.
The Detroit side between Outer Drive and Cadieux is East English Village. Better housing stock, can still run up to 150K but again is on the downward slide.
Finally the other side of Outer Drive you have Morningside. That area is bad.
Wayburn is the western most street in GPP. If you are on the "odd" side of the street your backyard abuts Detroit property. This is considered highly undesirable to many people. Barrington is the equivalent to Wayburn but south of Jefferson. The houses on that section of Alter are much better kept though. Also Alter is divided from the main part of Detroit in that area by a creek so there is less "exposure." Living on Alter will give you no GPP advantages.
So there was more than you ever wanted to know about Grosse Pointe borders

Obviously different areas have slightly different issues.
I have lived on the 1400 block in GPP (that is the first block off Mack). Biggest problem is walk in thefts from people that don't lock doors or garages. For instance a purse taken off a table, a bike from a open garage.
The police and observant and catch a lot. It can be obvious when someone is wheeling a snow blower down the street in July

I can't tell you theft rates are any higher or lower per block, best to just keep things locked and avoid problems.