ANA vs Singapore First from US to Japan

I have the options of either:

• NH111 from ORD to HND
• SQ11 from LAX to NRT

Both are in first, and are on the same day. I'd be positioning from a smaller airport on the east coast. Chicago is definitely easier to get to, but could be more prone to delays if there's winter weather.

How do the two compare? I've flown ANA first before, but not Singapore. The level of service in ANA first was great last time. I've heard mostly good things about Singapore, but also some mixed reviews.