Data for the first try: presoaked for 6 minutes (I was busy...), 60 minutes standing development with gentle agitation in the first minute and three turns after 30 minutes. I used 1.5 gram/litre potassium bromide in the mixture. The result with the pushed GP3 is very pleasing for the first attempt. As you can see in the pictures, the GP3 took the treatment very good. I took the pictures with my trusty Seagull 4A (Rolleiflex clone), not the first choice for a quick shot. When the old bus appeared, I simply estimated time and aperture and hoped the best. Must be 1/8 second with aparture around 5.6, if my old mind serves me right. You can take these long times with a TLR hanging on a neckstrap and a little luck.
The Shanghai GP3 100 ist the cheapest medium format film available at the moment. You pay around 18 Euro for 10 rolls on ebay. Please do not mix it up with the Lucky films, this is a different story. The GP3 has a reasonable fine grain, a good tonality and, as you can see, could be used not only at 100 ASA. It is not a perfect film. Being an old type emulsion, you should use hardener and should avoid toching the emulsion when wet. It is prone to failure when stored to hot or in a humid environment. If this happens to you, its possible to read the numbers from the backing paper on your pictures. And of course the small tape at the end of the film has no gum on it...
If you want to see more pictures, look at my flickr account: http://www.flickr.com/photos/24469035@N02/