We all have our favourite mounts and this is fine. Basically there is nothing wrong with any of them.

For years I had horse mounts. I was just not interested in anything else.

It was only when I came across a post relating to ride smoothness that I started to think a little more about the type of mount I was using.

"Stumble" is something where in game the mount crosses an uneven ground area and effectively slows down. This is correct and for me realistic towards real life.

A cat or wolf mount over the same ground does not have a similar stumble effect. This is maybe due to a slightly longer gait on cat/wolf mounts and this for me also follows real life.

So now I have changed all my characters to cat mounts. Not really to be faster but more because the ride is smoother.

For me a smoother ride lets my eyes focus more on the environment and I feel the mount and character are so much more fluid in their movement.

Each mount has its own characteristics and I am not saying they should all be the same. I just want to let you think a little for your choice.

My choices would be;

PVE questing: anything is fine
PVE farming cat/wolf mount
PVP cat/wolf mount (and also not a glowy mount as when you press "h" you present a big white light to any other players in your visual range)

If you want to check the Stumble effect then I suggest you go to Shadowfen, Stormhold. From the wayshine to the town is a stone bridge with a step in it.

There is noticeable stumble in the direction of the town and not really any when coming back to the wayshrine. Just try using different mounts and see what you think.