I had a Nagaoka MP500 that I recently sold with a turntable. It's a very good MM cartridge, but was bested by most of my other cartridges which include Clearaudio Virtuoso Wood, Hana SL, Soundsmith Aida II, Denon DL 301 MK2, and Zu Denon DL 103.
I have some other higher end MC carts, but they would not be a fair comparison to the Nagaoka since they cost much more.
The Nagaoka is a little better than my old Shure V15 Type IV with a Jico SAS stylus, being a little more neutral.
At their current prices, I don't see the Nagaoka as being a "bargain". I bought mine from a seller in Japan for quite a bit less than they go for here in the US.
I wouldn't try to steer someone away from a Nagaoka, but I think there are other options in that price range or near that are better. Stylus replacement is pretty expensive.