I usually use postback urls, but for this new campaign I only have a choice of javascript, image, or iframe to plug into p202. Any feedback on which of these would be the most reliable?
I think partly it depends also on your web server. If you are on shared hosting, you have to account for your server being busy to handle the request when it comes.
I'm using a vps @ beyond so server issue shouldn't be too much of an issue. Know there are a few situations where javascript could not be recorded, though rare. Just wasn't sure if images or iframes had any technical issues with them which could cause them to be more or less reliable than a jscript pixel
I am using cpvlab so I cannot comment on p202's performance. But I would go with image because the code to invoke is shorter compared to javascript. IMHO this should give you a better performance if you are doing high volume.
Can you put the postback URL inside an iframe or image tags and use that as a pixel? If you can dynamically insert tokens into it for this campaign it should work the same, would basically be a postback URL loaded by the client rather than the affiliate networks server.