Guy, I'm a diehard NP fan myself having killed a few elk with both bullet brands out of a 280 RCBS. Both brands performed with one shot kills on 4 elk.
What started my re-look at the SBT GK, I couldn't find any NP's. So, I started reading the good reports of 7mm/175 GK's on big game, bought a box and decided to test them out dry paper.
It was an eye opener I didn't expect them to stay with the NP. They do, and with more consistent accuracy and speed for longer ranges.
Sierra says this about them, "7 mm/.284 Caliber (.284) 175 gr. SBT
For rifles, this 175 grain #1940 Spitzer Boat Tail bullet is an excellent choice for most large game hunting applications. It has a heavy, double-tapered jacket and a special alloy core to ensure deep penetration and good expansion on the heaviest North American game and on heavy African plains game. It has the same basic ballistic shape as Sierra's famous 168 grain 7mm MatchKing bullet. Accuracy of this hunting bullet approaches that of the MatchKing, making this the best long-range big game bullet for any of the 7mm magnum cartridges. It is also used successfully in centerfire rifle silhouette matches."
I have an area I elk hunt that is flat sagebrush country, nothing but long shots. I'm going the Sierra bullet with no hesitation.
At $36.00 for a hundred I get a lot of practice with them.
