Hi @bigtomwpo
I think none of your options ??
It depends on how you use it.
If on desktop your page talks about apples and on mobile the same page talks about shoes, that page will have big penalties => Bad.
If on mobile you use it to remove SEO relevant items like titles, subtitles… => Bad.
If on mobile you have a lighter page, topic is the same => Good.
If on mobile the weight of the page is similar, and you use it just to solve some layout or design issues => Not a big impact.
However, this is based on common sense rather than on statistics.
Having a statistic to support my words is a little complicated.
The number of installations is still not very high, and the SEO results are always based on medium-long periods of time. Comparing with and without mobile versions is not so easy.
It’s not a matter of performing some quick tests and compare the results. For giving answers based on numbers you should monitor some websites in periods with mobile versions, and other periods without mobile versions, being careful that all the other parameters that are SEO relevant are kept the same as much as possible. This was never done.
I suggest you ask the same questions to SEO experts. I did it when Specific Content For Mobile was still only an idea, but never received sure answers. Maybe you will be lucky ??
Have a great day!
Jose
