The Alexa Plus AI has been in early access for over a year, but this week all that changes, starting with a Thursday preview at Amazon's upcoming Super Bowl ad featuring Chris Hemsworth. Let's look at how our phones and smart speakers are getting this smart voice assistant upgrade.

I've been reviewing beta Alexa Plus over the past year and found the AI upgrade to be highly conversational and more capable than the old Alexa, bringing new ties to third-party apps like Uber and Ticketmaster. Starting on Tuesday, Amazon has completed its rollout and made Alexa Plus available to anyone who wants to try it in the US.

It's no wonder Hemsworth got worried at just how responsive the voice assistant could be. The rogue AI scenarios in the Super Bowl ad playfully acknowledge people's fears over inviting generative artificial intelligence into their private lives as the Australian actor gets hacked by a garage door, drowned in his pool and mauled by an Alexa-ordered bear.

Amazon makes it clear that no damage was ultimately done. 

"By casting Chris Hemsworth, the last guy on the planet you'd expect to be scared of anything, we were able to lean into the conversation and put people at ease through humor," said Jo Shoesmith, Amazon's global chief creative officer.

Alexa Plus arrives with a free version and more

So, what does this new Alexa Plus expansion -- available now -- include? The most interesting part is several tiers of the AI's service, starting with a free version that anyone can use as long as they have the Alexa app downloaded or visit the web portal Alexa.com (which we've also tried).

You won't get any advanced Amazon Echo capabilities that way, but you will be able to test out Alexa's conversational AI and see how similar it is to talking to a human. Alexa Plus errs on the side of chatty, but its ability to summarize answers, stop in mid-conversation and answer follow-up questions is welcome. As I've said before, it feels like what voice assistants were always supposed to be like.

"Alexa Plus is built to make customers' lives meaningfully easier -- and that starts with conversation. Because Alexa Plus lives in the middle of everyday life, it has to be natural and trustworthy," Panos Panay, senior vice president at Amazon Devices & Services, tells CNET. "The Super Bowl is the perfect moment to introduce this evolution at scale."

Two other Alexa AI tiers exist. The first comes when you subscribe to Amazon Prime for $15 per month. That unlocks not only Prime's own content but also all Alexa Plus capabilities across all compatible devices. This includes Echo smart speakers and AI video summaries for Ring security cameras, among other tricks. You can try telling your Echo device to "Upgrade to Alexa Plus" to get started.

The final option is paying $20 per month to unlock all Alexa Plus capabilities across all devices, independent of an Amazon Prime subscription. Alexa won't be able to interact with Prime content like videos or Amazon Music, but it can connect with everything else the AI upgrade offers. Since you need an Amazon account either way, this tier is for specific people who want to avoid Prime content.

Is the new Alexa AI worth your time?

If you're wondering whether Alexa Plus is worth it compared to alternatives like Gemini for Home or whatever Apple is cooking up with Siri, I found my experience with the voice assistant to be the most positive I've had overall. Sometimes a little too positive -- as we've seen with chatbots, Alexa Plus can be very willing to agree with you and promise to do anything, even if it can't.

Also, if you use an Echo, it will send your voice recordings to Amazon for automatic analysis; there's no getting around that privacy concession if you want Alexa on a smart device.

Those issues aside, Alexa Plus as part of Amazon Prime for $15 is an excellent deal, especially if you already use Prime for ordering, catching up on Fallout, etc. If you're not sure how talking to the new and vivacious Alexa feels like, all you need is an Amazon account to try it out online.