exchanging D7000 for D300s - am I crazy?

I've had a D7000 for a couple weeks and two things are bugging me:

1. The grip is the pits. Just too small for my large hands.

2. I've determined mine has backfocus. I can get repeatable improved results by adjusting the AF fine tune to -15 for both my 18-105VR and 35/1.8. This seems a bit of an excessive (but consistent) adjustment.

I'm going to return the D7000 anyway because of #2. But #1 is leading me to just replace it with a D300s. So, my question is, am I really going backwards here for low-light IQ? I am pleased with the D7000's ISO 3200 and do not need to go beyond that. I'm wondering if the D300s at ISO 3200 is really that much worse than the D7000. I'm not necessarily a pixel-peeper and am experienced in applying post-processing noise-reduction tools... but I am a stickler for sharp data off the sensor.

I really want a D400 but I need a camera now, not next Summer.

Thoughts?