[sdiy] A (slightly) better VRef?

[Justin Owen]

Sorry to be flooding the list like this...

Hoping for some VRef advice: http://www.sdiy.org/juz/voltage_reference_01.pdf
 
For VRefs I've always used the 2xR voltage divider into an op-amp buffer shown in Ex. 1. It's simple, it works but I've been wondering if there might be a small step up?

Would there be any advantage in using Ex. 2 over Ex. 1?

Is there something else you'd suggest that was better than 1 but not necessarily up to LM317 level?

Thanks again.