Granberg Ripping chain is SPECIAL. It's got two different angles on the cutters. Over on Arborist (WHICH IS DOWN DUE TO HACKING

) one of the peeps, (mntgun?) did a lot of time tests and, if I remember correctly, only found a slight improvement with Granberg over regular ripping chain.
If you only have a few regular chains many guys just use a regular chain (cutter with about a 35 degree angle) and just gradually sharpen it down to a 10 to 15 degree angle.
Big things are to keep your rakers down and your chain sharp. On a 10' cut of 20" maple I usually took a break each pass and hand filed the cutters. Only a few swipes were needed but it made a big difference.
Soap - those slabs look GOOD. Be sure to sticker and paint the ends. Are you going to plane them?