While I initially didn't like the idea of hunting down aftermarket IR's, I soon found the swings in tonality between all the factory cabs (especially from different companies) was yet another variable that I did not want to play around with, so I've invested in a few Ownhammer packs. I find the OH stuff to be the most balanced of the aftermarket IR's I've tried and they complement the Fractal very nicely.
Last night I picked up the Super Reverb pack to go along with my Deluxe Reverb, California Duo, and old 4x12 Marshall pack. The Super Reverb isn't drastically different than the Deluxe, just a little different tonality with the smaller speakers. There's a lot of variety there. The Super and Deluxe pretty much cover the basic spectrum of Fender clean tones, the 2x12 Mesa 3/4 can cover a lot of the Class A type tones, and the 4x12 Mesa can cover most of the gain stuff.
I also cleaned up my user IR cabs, adding three IR's for each cab/speaker (57, 121, and OH1F). After a lot of trial and error using different mixes, I ended up preferring the 121 90% of the time because it is warm and full yet has some clarity on top. I added the 57 because it's a classic selection and the OH1F because it's a blend of the two. Everything was pulled from the quick mix folder as I don't want to audition thousands of IR's.
I'll probably pick up the 4x12 Marshall EV soon as it's a very different speaker from anything I've got right now...and hitting the volume discount makes it easier to pull the trigger!