Simple question, what is your god honest anwser to what sounds best with vorbis.

What is the best size to quality ratio on vorbis? 128? 160? what range should i use?

Don't use bitrate settings use the Quality settings. I use --q4.75 which I think is pretty good. I have here people talk about a range form 3 to 6 for average

I use 4.99 as a quality index. I read using 5 boost the bitrate too much for the increase of 0.01.

nice to know there is a few familiar faces here sawg

Well it's quite simple - the higher the quality level, the better the encoded music will sound

Beyond that, it's up to you. What bitrates do you normally use when you encode MP3s? The default quality (3), will produce around 112kpbs files, that sound on a par with most 128kpbs MP3 files you'll find. Quality 4 is around 128kpbs, and quality 5 around 160kpbs.

Slightly complicating the matter is that you can choose non integer quality levels as well. These are intended to increase the bitrate smoothly, and mostly works very well. The exception is a large jump between quality 4.99 and quality 5 -- several setting get turned on at quality 5 and upwards which increase the bitrate usage.

Myself, I'm using quality 5.1, which is a nominal bitrate of 163kpbs.

Yeah, I've also noticed that 5 is a big jump in quality over 4.99... perhaps deserving of the increase in bitrate. On some of my ogg problem clips, I have a much easier time ABXing at 4.99 than I do at 5.0 (although I can still do it at 5.0, I just need to pay a lot more attention).
People have different thresholds of what's annoying... the best advice is to test some clips for yourself and see where you stop noticeing a difference, or at least stop being annoyed.

Hi tim, have you ever tried to see if you can ABX between the lossy and lossless stereo versions of -q 5.0 ?

I haven't tried the altered version of oggdrop, so I don't know.