Has anyone tried any of the Smart Helmets with the walkie talkie feature? Looking for better communication with my stoker.

If you aren't already using CatEars (https://www.cat-ears.com/) I'd start with those to reduce wind noise and see if that solves the communications issue.

We haven't tried anything integrated into a helmet but I'll share our experience with two other solutions:

We used to use wired TandemCom headsets years ago but gave up on them after the system started to develop static from bad connections that weren't solved by new headsets, so the problem seemed to be at the connection on the main unit. Advantages of those were long battery life, ability to listed to shared music, and comfortable headsets. Also not terribly expensive for what they do. Disadvantage was it was a wired unit which is a bit of a hassle and I think we had some issues with the headsets after riding in torrential rains and had to replace several headsets due to the wires going bad. I think you can still find these at tandem dealers.

We recently purchased the Cardo Bk-1 (aka Terrano-X) system which is wireless and attaches to the helmet. Advantages: decent battery life, comfortable, functions as a phone headset. Can be set up over only the right ear so you can still hear traffic or can be set up over both ears for stereo (if you're riding off road or away from cars). Disadvantages: pricey, no shared music, delayed audio due to digital transmission, some extra background noise at times from wind. It sometimes disconnects and it takes 20 or 30 seconds to reconnect. Fatal disadvantage: If it was too noisy to hear each other without the headset, it was too noisy to hear each other with the headset! If it was quiet enough to hear each other directly the digital delay was an issue and actually made it harder to communicate. We stopped using these on the tandem after just a handful of rides.

I do use my headset every day on my commute to listen to music and podcasts and occasionally as a phone headset. I do have to say I'm amazed at the wind noise cancellation of this headset. I can carry on a phone conversation while descending a hill at 30 mph and the other party has no trouble hearing me. Above 25 mph I sometimes have trouble hearing them unless I turn the volume way up and place the speaker very close to my ear. That's with Cat Ears blocking the wind. We do use these headsets when riding singles. This is what they're designed and marketed for and they work well in that application. We can carry on a conversation like we do on the tandem even when riding singles, and the delay isn't an issue when you're too far apart to also hear each other directly.

My wife and I bought the Terrano-X system so we could chat while riding single bikes together, and found that system to be perfect when we got a tandem.

I see two very different comments, and appreciate both.
We have used "Sena" SMH 10 , for 5 seasons. They are adapted from the motorcycle crowd, they work well for communicating, we are a 140 Y.O. team and both wear hearing aids.
Pros: The close proximity of the mic helps clarity and noise, more economical than Terrano, they will do bluetooth music although we have never used that feature. Work fair in connecting to cell phone.
Cons: They are a pain to mount, as they are not made for a bike helmet, it's a total "engineer it yourself" mount which I realize is not for everyone.Wind noise seems to get the upper hand in the 18-20 mph range.
Due to the fact they are mounted on one side of the helmet, the weight "tips" the helmet.

This Sena is NOT voice controlled, so no delay, battery life is over a days ride use.
The Sena batteries are not replaceable, so I had planned on "upgrading " to the Terrano, Alan's comments make me wonder if that is an upgrade.
I do notice they have more products available on their website (sena.com)
Just some thoughts
R&J

I have 2 SENA X1. Only used the walkie talkie feature in the store; seemed ok.
The main reason I got those were for the blue tooth connectivity to phones; music,
answer/make calls:

2018 FIVE BORO BIKE TOUR by 1nterceptor, on Flickr

BROMPTON HELMET AND BIKE by 1nterceptor, on Flickr