Question about passive and active subs for Atmos

[6foot4design]

We are in the process of building up our main mix room to be Atmos certified. Our current sub is a little bit under powered and we are on the search for a new one. We have the MTRX with the SPQ card that is going to be doing all of the management, filtering as needed, delays, etc.

The Dolby certification spreadsheet lists a whole bunch of passive cinema subs, along with the regular powered subs for recording studios. For instance, the Genelec 7382A gets us over the hump to be qualified, but the damn thing is $10.5k! Alternatively, we could go with something like a passive Christie S118LP that is around $1000 that also gets us over the hump in terms of power. We would also need an amp of course, but it is still a huge price difference at the end of the day. I know there are things like AES inputs and that sort of thing that make it more expensive,

I'm curious if there would be a huge difference from an listening/mixing perspective, with the nature of LFE, between the 2?

What are you getting for that extra $7-8K (after we get an amp as well)

Thanks!