If you live in North America, expect 100-150ms ping. It is playable for survival but terrible for PvP. Additionally, their Java version updates lag by about 2-3 weeks (hence "Slightly UPD").
These are arguably the most popular, but offer true 24/7, always-on hosting. They go to sleep, but are very easy to wake up. Best Free Minecraft Server Hosting 24 7 UPD