I just made the crossover from EZD to SD. My question is, what is the difference with the SDX and EZX in terms of overall sound? I have every rock and metal EZX pack, but haven't bought an SDX pack yet. Is there really a huge sound quality difference using the SDX vs EZX in SD2?
 
I do notice there's significantly more midi files with the SDX.
 
 

SD2 has many more layers of recorded hits than EZ. This means there are samples to work with which can help you achieve more detail if needed. 
The mic bleed options are extensive and very user friendly. You have full control over how much each mic contributes or not to the sound of one kit piece. 
The X-drum feature is great for mixing different kit pieces for SD2 and EZ kits. 
I only use SD2's Avatar but I do have a few kits from EZ such as Latin, Nashille, and others. 
 

SDX are 24 bit and EZX 16 bit but I don't think that make a great deal of real difference. Its more the features Rimshot noted that make the difference.

Oh you are in for a treat! SD2 is a whole other BEAST compared to EZDrummer. Just the mixer is worth it IMO. Have fun and good luck

Hey ProjectM! Good to see you!
 
On another note, SD2's screen is very small and not adjustable in size compared to more modern screens. It has become a problem for me and many of us current users have been waiting years for a SD3! Just be aware of that. In the meantime, it performs extremely well. 
 
 
 
 

Also, if you want to use the EZX kits in SD2, for some reason it takes a VERY long time to load the EZX kit! No matter if you aren't playing live but seems like a lifetime. The SDXs load fine but that wait for an EZX is sometimes excruciating. I have really heard no difference in the sound quality of the EZX in SD2.

I think of the two this way.

EZDrummer2 is pretty much "produced" for you. You "produce" SD2. IOW SD2 is more raw and awaiting your treatment.

i can hear an obvious difference between the quality of the SD2 samples and EZ.
 
they both have their strengths,
it's a lot quicker to get running with EZ,
but if you are looking for the best quality sound,
SD2 is the obvious choice.
 
 
you control the entire mix of the kit just the same as you would in a studio with a live kit.
 
if you want your sound to be built around close mics.....
or room mics....
mono mixes, wide stereo...
it's very easy to build the sound platform in SD2.

Sidroe
Also, if you want to use the EZX kits in SD2, for some reason it takes a VERY long time to load the EZX kit! No matter if you aren't playing live but seems like a lifetime. The SDXs load fine but that wait for an EZX is sometimes excruciating. I have really heard no difference in the sound quality of the EZX in SD2.

I have not seen this problem myself.  EZX and SDX kits both load approximately the same for me.
 
bapu and rimshot are correct in their assessments - i can't add anything to what they've said except that I have tried and tried to use EZX in songs lately and keep going back to SDX because I can't seem to find the right "sound" for the kit in any of the EZX any more!  SDX is where it's at!  I love it!

I have both. After a brief comparison I've come across an interesting observation - the same sound set (from EZX obviously) with the same preset sounds slightly different in EZD2 vs SD2. I presume it is due to internal bleed routing differences.