[angry_octet]

There are some high karma accounts which make a great contribution, and others which ... don't. I'm doubtful whether karma or account age has a significant signal beyond anti-spam.

But it would be useful to know if I had up/down voted them significantly in the past.

[krapp]

The only thing karma reliably indicates is participation over time, the signal is too noisy for anything else. If anything high karma should be a red flag. The very best contributors here rarely comment because they have better things to do. It shows an 8/8 score for me and I doubt anyone would consider me a top tier high quality contributor.

A plugin like HN Comments Owl would be more useful IMHO.

[angry_octet]

As if to demonstrate my point, two high karma accounts have down voted my suggestion that karma is meaningful. Naturally they are too craven to enter the field.