I don't understand all the dismissive replies.
The 300s are heavy, yes, but also strong, comfortable for shoes of all types and sizes, inexpensive, they have servicable bearings, and they probably provide decent traction in wet conditions without eating up your shoes.
They are also wide, and I understand the dangers of wide pedals when riding fixed, but in my estimation the difference in ground clearance between the 3000s and GR-9s is at most a centimeter and a half (when the bike is leaning at 45 degrees), but this is the same difference in bb drop between some popular 'track' frames.
Am I going to ride barefoot? No. Am I going to use this setup on the track? No. Am I going to use it on the street? Probably not. But it seems like a viable setup, and maybe it suits someone else's needs.