Since there isn't a perfect station that ticks all the boxes there is always going to be pros and cons....that said...
For me the biggest difference with the Acurite Atlas versus the Ambient WS-2xxx was the ability to publish my data anywhere I wanted/needed. With my Ambient Station I'm able to easily publish to all weather sites, my own website (for future consideration), my own SQL database for backup, and I'm able to run 3rd party weather software (Meteobridge, WeeWx, Weather-Display). In particular was the ability to have a CWOP/MADIS station.
With the Acurite Atlas right now you are limited to just having your data on WU, and myAcuite.com, and you can manually pull an SD card out of the console and do manual backups I suppose....but that seems ridiculous as it can't be automated and does nothing for helping to publish elsewhere. The Acurite closed product design tells someone like me that Acurite doesn't care about the person that wants to do more with their data. If you are happy with those limited choices then that is totally fine. Everyone is different.
Most importantly this newest Ambient hardware is much improved over the prior generation. That review posted earlier in this thread has an error. It mentioned that the older generation uses the same sensor suite but the new model is in a different package. That is not true. The new Ambient stations have newer generation Sensirion sensors SHT30 that are almost as good as the SHT31 in the Atlas and Davis systems. If more perfect data especially at lower than 10% humidity is important to you then don't get the Ambient.
Acurite could change and give new features to the Access with a firmware update. But I feel they need to deliver before they deserve my sale and my recommendation. I'm hoping they do reflect on what I'm saying as I see much potential in their new Atlas product line. A stronger Acurite system will only force Davis to also get off their lazy complacent laurels and wake up from 1986 and get back to the current decade. It is my hope that by the time the Atlas Elite launches that it truly becomes a VP2 killer. That way the VP3 can be that much better. It is healthy competition that keeps us happy. It is bad to be a specific manufacture fanboy....all you do is hinder product innovation with your biased product endorsement and recommendation and your blind eye to product issues and shortcomings.
Ambient has their issues too. All in one design is a limitation. Lesser sensor part model. Limited console range compared to Davis....etc. I tell it like it is. No sugar coating. Make your own pros and cons table and then decide what is important for you.