Perhaps you can't decide which processor to buy, you can make a decision by looking at the Apple M1 Ultra GeekBench 5 score multi and single core test and understand is it a good processor or a bad one to buy, how powerful is this processor. Here is all information from GeekBench 5 benchmark. A thorough review of all the specifications, so that it can be easier to understand, is summarized in the table. After looking at the data of joint test and video, you already be able to know do you need to buy Apple M1 Ultra or not.
All the data in the table above do not mean that taking them into account you should entirely trust a simple quantitative comparison. Be sure to watch the testing video and read the reviews of real owners of Apple M1 Ultra before deciding buy this processor or not.