I used my iPhone to upload pictures to this site yesterday and made a couple of forum posts. It seemed to work well enough. The banner ads at the bottom were a pain as they limited viewing of content rather a lot. Made forum replies a challenge. My eyesight is ok with my readers and phone resolution settings are default. Having a reader version option for pages would cut out most of the ads and improve mobile viewing greatly. Hint-hint.
I mostly use my iOS tablet (iPad) but use my iPhone if I'm uploading pictures, avoiding having to deal with importing pics from phone(which I generally use for taking pics) to another device. I don't use my laptop much in the spring-summer-fall. Why? Because I'm outside as much as I can be! We have a desktop still, but usually HE uses it for work. I had an old laptop I used to take outside, but we've hooked it up to the family room TV. My new purple laptop is too pricey and precious to me to haul around outdoors. I probably wouldn't be able to easily replace it either. It was built for me for my gaming business, so I am rather proud of it.
Mobile use continues to rise, with desktops almost considered archaic and even laptop popularity falling to tablets, tabletphones, and smartphones. Might I suggest that having the site be as mobile-friendly as possible should be a priority?