I'm not sure grooves on a putter will make the slightest difference at all - can't remember the last time I managed any compression of a ball with a putter. Peripheral weighting, creating a larger sweet spot I can understand, but that takes the skill away when using toe hits for fast downhill putts.
Personally, I think the manufacturers have taken licence with the lack of regulations on putters for donkeys years and created a marketing fuelled monster of a business in a part of the game that is the easiest.
Personally, I think the manufacturers have taken licence with the lack of regulations on putters for donkeys years and created a marketing fuelled monster of a business in a part of the game that is the easiest.