Probably the one I returned
I went from Max base model to Ultra model and back when I realized the Ultra model was practically no faster in video editing (even effects, titles) than the Max model. Sometimes my laptop (a 32 core Max) was faster than the ultra in exports and playback! It made no sense.
I couldn’t justify the extra $1700 (refurb prices) for a jump to 64gb and 1 TB storage which essentially was all I was paying for.
What a shame. The Ultra showed so much promise but the extra video encode decode engines, the extra neural engine, are currently not used. And the GPU is highly constrained as the core counts go up.
IF however you do CPU limited tasks like Lightroom - or work with a lot of RAW video footage (I don’t; all of mine is compressed), the Ultra is a lot faster. So YMMV