Suzuki 2 Strokes

Does anyone know why Suzuki switched from the older style T500 / GT750 ported pistons to the newer non-ported style they have available now? Do they provide different performance? I know the first year of two for the T500 used these and that happened to be the highest HP years for bike.

Supposedly, the bottoms of the port windows on the pistons tend to break with ugly consequences.....

Good to know...I hadn't heard they had this problem. No doubt that would be a major issue.