I like the 100gr. Partition, it works really well. I DO practice with the 100gr. Sierras (same powder charge, and both loads hit the same POI, so the less costly Sierras make for good practice bullets). I would have no worries using the 100gr. Sierras if it came to that, though (100gr. flatbased ProHunters).
I see little use in using the Noslers for practice when the Sierras hit at the same POI at half the price.