Regarding the IE5 bug, that's the one tremendous hurt associated with the current nsvhr that I know of, however, it's also a hurt associated with Apache 2.0, and one that at least one Apache developer is trying to eliminate. Fun, is that there was a fix for it in Apache 1.xx, but no one seems to know what the fix was or the details why. (That's that IE 5 and IE 6 (I believe) will occasionally have problems POSTing through nsvhr if the POST is large. Unfortunately, it's not clear what large is, it appears to occur somewhere over 1K.) Does it occur commonly? I believe it depends on your site and what you ask the user's to POST. I encounter it with OpenACS 3.2.5 using the prototyper in which POSTS commonly are about 8K long consisting of a bunch of autogenned Tcl.
No, you can't use it with SSL.
I don't know of any other problems with nsvhr, but the cool part of my development with nsvhr (and almost any other piece of software) has always been that just as I think I've seen no bugs for many many months, along comes some new (to me) behavior that is just completely bonkers.
There's a small sweet spot for nsvhr/nsunix. If your sites get so popular you want to put them on their own machine, than you have to use a tcp socket based solution: nsvhr/nssock, Apache, or SQUID. Also, why it is very nice that nsvhr makes adding a new proxy easy to do and doesn't require taking down ANY aolservers, it's also a bit of a pain, that each AOLserver becomes rather piggy. Most likely you can only have somewhere between 4 and 16, or 4 and 32 AOLserver sites hosted on one machine. Contrast that with an inprocess virtual hosting technology....
To sum it up, if I had to do it again, I'd have used an Apache or SQUID reverse proxy myself. I only got into it because AOL released it in their first 3.0 release and claimed it worked, and then it didn't, but someone came up with one patch that was supposed to have fixed it, and then the gods cursed me and I broke out gdb one day trying to understand why I was the one that couldn't get this released package to work.
