Best player for REX2 files?

Have you tried RXP?
https://www.cakewalk.com/Documentation?product=SONAR&language=3&help=Plug-ins.4.html#1766315
 

A little update... in Kontakt 5:
 
1) Load a Rex
2) Click Wave Editor
3) Click Sync/Slice
4) Click Auto Find Empty Keys
5) Click the Powerbutton Next to Grid
 
It seems to lay out each of the slices on my keyboard and then have the loop playing on all the rest of the keys going up the keyboard.
 
Did I just solve my issue? Is that the best way to do this with Kontakt or is there a button/option I could be clicking that would make it even easier/quicker?

Thanks

Well - it's not a simple "player" at all by any means, but I really love to "play around" with REX/REX2 files by importing them in Stylus RMX (from Spectrasonics). Once imported there are so may way's you can manipulate them. With the time designer you can make any drum loop (or other instrument loop) fit in any arrangement, and having the possibility to give slices (or groups of slices) give their own individual FX effect does not hurt either.
 
It is not cheap, but for me Stylus is one of the first things I use when I want to manipulate REX files. Still... The other named programs (like Battery) are a very good option too..

Related info from another Cake forum thread:  http://forum.cakewalk.com/FindPost/3381014 

 So, how does one preview THOUSANDS of .RX2 samples without having to load a DAW?

Turns out the free UVI Workstation has a built-in .RX2 sample player! I installed all of the sample folders in a '9V Audio' folder under my 'Loops - Audio' folder under 'My Documents'. To get to it with the UVI Workstation, you need to navigate from Devices, through C:, the Users folder, the current user folder, then the Documents folder. You get the idea. Highlight a sample, and it plays. Use the down arrow key to move through the samples. Works great!

http://www.uvi.net/en/sof.are/uvi-workstation.html

 
further down on same thread: http://forum.cakewalk.com/FindPost/3381120 

So can Beatscape (play REX files). It's the only 32 bit plug I use in Sonar. It will also work in FL Studio.

 
further down on same thread: http://forum.cakewalk.com/FindPost/3380975 

Reaper has a batch file convert (under the file menu) will convert them (REX files) to .wav in bulk.  Seems to do a really nice job.  Sonar seems to get really confused on a bunch of these .rx2 files.  It pulls all kinds of odd tempos and mashes the slices something awful.  Pretty disappointed in Sonar's REX file handling with these. 
 
So far Reaper's batch convert to wave seems the best thing I've tried.  You can drag and drop directories into the batch converter, so you can do a whole bunch in one go.  Disc space is a bit of an issue and you have to put the files somewhere but it's not unreasonable.
 

 

Wow it's perfect in UVI Workstation... Just click the Map button to switch to slices, and it even lets you drag in the notes perfectly as MIDI... which I'm not quite sure how that even works since I didn't realized midi data was stored in these Rex files.
 
Love it. Guess I'm buying that collection.