I’m kind of shocked that we’re all in agreement here, but I also have Ultras and Streaming Stick+ throughout my house. I started with just one Streaming Stick for years, but after falling deeply in love with it, I then put in Rokus on every TV. When you can hardwire them, do it. For every reason. Wireless will work just fine, but it’s a strain on your wireless network, and one more thing to worry about.
As for which model to get, I got my two Ultras on a Black Friday deal at Wal-Mart as an afterthought and I love it. I love that I can customize the “find remote” sound it plays. I love the integrated TV power and volume buttons. I never use the voice option, but my 6-year-old loves it. One other feature I use from time to time: the built-in headphone jack on my Ultra remote. SUPER nice to be able to plug in headphones if I’m up early or late and don’t want to bother the rest of the family. You may not need that so it wouldn’t matter.
The primary differences between the Streaming Stick and Streaming Stick+ are the “advanced range” of the +, but I never had a problem with range anyway. The + also does HDR and 4k, but I don’t have HDR or 4K TVs, so I don’t care about those features. That’s all that separates them.
If you don’t need TV Power and Volume controls on the remote, 4K or HDR, and your wifi is extremely underutilized, you can even look at the Express. But for the MIMO on the Streaming Stick and the additional power and volume buttons, I wouldn’t personally go lower than that.
You can go here to compare the models: https://www.roku.com/products/compare