The 300mm lens is a classic in photography.
I first had a 300mm on my old manual focus Nikon. You needed a pipe wrench to focus the thing. It was both photography and a nordic workout at the same time.
Then I had a small 300 f4 for Pentax, it had internal focus which was a nice feature at the time. I up-dated that lens to a newer version of the 300 f4, I think that one was an Ed lens.
Then I went back to Nikon and used the 300 f4 AF, then the 300 f2.8 AF. I even borrowed the Nikon 300 f2 for a game. Huge piece of glass, hard to get in focus, wasn't on the market all that long.
Then I bought a 250mm for the Hasselblad to shoot NBA. Not quite a 300mm but still in the range.
Then switched to Canon and bought a 300 f2.8 which was ruined in a storm while shooting sailing. Then replaced it with another 300 f2.8.
Then I bought a Schneider 300 f5.6 for my 8x10 camera and hauled it around the woods for a couple years before replacing it with the Fujinon 300 f8 that I still use on my 4X10.
Then I started shooting with a Pentax 645 AF and bought the 300 f4 AF for portraits.
Finally after all those years and lenses I'm using the Sony 300mm f2.8 AF on the new A77.
You know what, I've loved the 300mm for along time but I have to admit, the 70-400G is easier to use, more flexible and I think it might actually focus faster. Wow, I'm tired just thinking about it but really the zoom lens might be a better solution. Especially since f-stop isn't as important when you can just crank up the ISO on the new sensors.
I'll try the zoom for hockey and then we'll know for sure.
These shots were all done with the Sony A77 and the 300 f2.8. All on burst mode which sets the lens to f3.5 and gives me 12 frames per second. ISO was 1000.