Well, I didn't really setup any newsgroup server (other than the one in IIS for fun), if that's what you mean by "first hand". But I do donated to one out a week worth of my lunch money when I was 13 years old because I frequented there and they needs some funding for their broken RAID card + drives.
> Outlook never supported NNTP
If you know a bit more, you should know that Outlook Express does, then Windows Live Mail etc. The reason why I'm using Thunderbird as email client is probably because it got a (even through buggy but) functional NNTP support. I also know Thunderbird has a bug which prevents it from using the correct charset defined by the user, because I guess I've spent too much time on these news groups.
Also, reading your reply, I realized that you are putting a lots if not all of your own experience on "plain text messages", and you're thinking "this is fine"? Then wake up. On today's Internet, if your forum service cannot host memes and other types of rich multimedia, it's already out of public view. So,
> "have no issues handling articles up to 750 Kb in size"
Dude, really? Just 750 Kb? :)
> the client would highlight unread messages
It require some setup that most people don't know they can do. "Filter" in Outlook Express if I remembered it correctly gives you a different color when a matching mail is received. But guess what, it's not the default at least during the time I'm using it. If you don't do that, you'll only get "notification" (actually, just count refreshing) every time when new mails are downloaded, even if none of those mails are meant for you.
Your overall reply gives me a feeling that you're deep inside your own good-old-time memories, which let you to give out these apologetic words. It's reasonable if you are an user, after all, it's indeed a good time for many of us. But one should not be blind by nostalgia, because if they did, they running into the risk of degenerate their own creativity for something far better. Seeing flaws don't prevent you from loving something, you know?