SP23_H1 any problems?

Hi List,
I'm planning to install SP23_H1 on our AS/400 V5R1 early March. I notice I can't find anything about it on the O/P site anymore. Just wanted to know if anyone has done this SP and how it went. Any problems or things I should be worried about?

Thanks,

The instructions for this Service Pack mention SAR 6911235 (JD22829). I can't find any info on this SAR. Does anyone know if this SAR is a requirement to do the Service Pack or is it to enable new functionality with security encryption? Basically I'm asking if I can do this ESU at a later date, post SP23.