Out of these two cartridges which would you choose?

Hi everyone i officially had my new mega rp8 for a week now and am amazed by the performance with it. I am looking to upgrade the cartridge now but can decide by these two after naming down my search. I have my sets set on either a dynavector 20x2 High output version or a new ortofon 2m Black. The preamp Im running it through would be a cary slp-98p Class A all Tube phono preamp with mm only. I am not considering a low output mc. Because I tried out a new pair of speakers for fun an shocked by how bloody good they sound with my system. But are worth 10K lol and are the last pair I will ever need for life!