Alright so I have both of these and I’m just going to give my opinion between the two….
The Ultra is definitely faster but it’s not a super huge difference compared to the streaming stick 4K. It’s not a “how did I ever live before I had the Ultra” thing. The remote is a different story.
The Voice Remote Pro 2 is a huge upgrade compared to the regular voice remote. The remote lights up when you pick it up. It has USB-C charging. It also has the shortcut, and guide button. In addition, it has a lost remote finder, and you don’t need to hold down a button for the voice function. You can just say “hey Roku,”. I’m unsure of the battery life, but seeing as it’s rechargeable, it shouldn’t be much of a concern.
The OS, under audio has a pass through option for the ultra. The streaming stick doesn’t have a pass through option for audio.