Most of us really do not need square ground chain, IMHO it is sort of a luxury. I round file all of my chisel chain, with the big HP saws I use it works great. (Soon to be grinding with the Super Jolly!)
If I was a pro faller out here in the Pacific NW big timber country yes, I would run square ground chain. A little faster on those big trees at 5 feet or more DBH. Time is money, don't linger at the stump!!!
I would love to have a Silvey, but I do not earn my living with a saw so it really is a pipe dream. About 3 years ago I saw one at a garage sale, an old faller I knew died and his tools were being disposed of. Only $500, but it did not compute at that time as I was not into milling then, just firewood cutting. Should have bought it!!!
Ripping chain works just fine round ground. Hit the Granberg site go to FAQ and read about grinding ripping chain. I have two loops of the Granberg and two loops of full comp (ground for milling) from Madsen's. Madsen's has an interesting paragraph in the catalog about ripping (milling) chain, if you are milling it is worth your time to read it.