Symmetric PSUs and negative voltage regs

[hollowman]

You've all seen the ubiquitous symmetric PSUs: +/- voltage outputs, using a pair of LM3x7: 317 for + regulation, and 337 for negative.
Somewhere in the archives I recall a discussion on the innate limitations of negative regulators like 337s. Don't recall the specifics, but some noted that for +/- requirements, it would be better to simply use two pos. regs (e.g. 317's), but wire the downstream ckt backwards.
Pun unintended (!), what are some positives and negatives of this approach?

[AndrewT]

read Jbau's thread.
He has measured and listened to 337 compared to 317 and 1085 and declares the 317 as the worst of this lot for his testing and listening arrangement.