I have the following kernels installed:

• linux-zen (Zen)
• linux-rt (RealTime)
• linux-hardened (Security Hardened)
• linux-lts (Long Term Support)
• linux-tr-lts (Realtime LTS)

When I boot up, I try the different kernels from time to time just to see if anything interesting happens. It never does.

My question: How do I actually physically notice the difference between these kernels? If I use RT, does Firefox spawn quicker (in my testing, no, not really)?

What are some use cases when I can really see the difference in these kernels?