I use Pan, the philosophy and interface is very like XNews.
I seem to recall reading somewhere that Pan's authors said they got a lot of their inspiration from XNews.
The only problem with Pan I've ever encountered is its unfortunate tendency to lock-up if you don't limit the number of headers you allow it to retrieve on each fetch cycle.
When I go into a new newsgroup, I usually just let XNews grab all
the headers. And I've done this in groups that have 100K+ of them. It might take XNews a while to pull them down, but I usually grab some coffee or play with the dog a bit, so it's not like it's that big a deal for me to wait every so often.
Pan, on the other hand, seems to crap out around the 40-60K header mark - even when it's running on the same hardware (I swap drives to switch between Linux and Windows ) as XNews.
Not a showstopper for Pan - but it makes me think when I'm going back and forth between OSs, so I'm not all that happy about it. Otherwise, Pan is as good as it gets on Linux. At least IMHO.