I have been using a RPi1 B+ (512MB RAM) for 2 months now as DHCP server for my local network. It is still running 11.0, sysupgrade ran fine but I still see version 11.0 after rebooting, I have to figure out what I am doing wrong.

Software installation is indeed slow, my booting times are not terrible though (running just sshd, ntpd and dhcpd probably helps).