Excellent sounds for a variety of music
Like all of the EZXs, the samples are uniformly fantastic and work great with the EZDrummer's sound engine. You'd have to put some work in to perfectly mimic a live performer for jazz but even with the quick-compose tools you can get pretty close. Good variety in the included MIDI (not always the case in some EZXs) and there are three available separate MIDI packs with a jazz focus that expand it.
A couple of reviews mentioned lacking a sizzle cymbal; the Americana EZX has a 19" Zildjian Armand “Beautiful Baby" Sizzle Ride that sounds great. The other drums in that EZX go very well with the jazz MIDI.
I just spent most of a day on the Toontrack website compiling a spreadsheet matrix of every EZX sample and kit combo to plan out my next buy and avoid duplicating (good news, out of over 1650 samples Toontrack only reused about 70 pieces among their whole EZX range).
There is an 18" Pearl Reference kick included in the Jazz EZX, but none of the EZXs have a Gretsch Catalina or any kind of Flat ride (my best drummer 25 years ago had one I loved and have been chasing a digital version of).