I really doubt they are any more powerful than the best x86 rack servers. Their featurefulness is super dated. They are definitely not cost effective (good luck buying it from IBM without a huge contract).
I pity the company that gets into mainframes today. Does that even exist?
It's a proprietary nightmare.
I do agree it is debatable whether it is beter than x86 most of the time cost savings projected when using a LinuxOne it is based on licensing. In the past oracle licenses where per core and we did a project where 8 ifl’s replaced 140 x86 cores
It seemed rather pointless to me. The DB2 server was serving queries just fine and when we were working on setting up a microservice that would allow viewing claims history, the storage and server costs for being able to provide queries against three years’s claims were prohibitive.
But they were still persisting down that road when I left.