I go solo and prefer the premier hotels for a few reasons.
They are close to the parks and can be a short walk or water taxi ride from hotel to the parks/city walk.
They also have decent availability for table service dining.
You can also order room service from their restaurants.
Sfalls is not a premier hotel but they also have table service dining.
I know the other hotels onsite have the bus service
Sfalls and Cbay are still close enough to walk from.
If money is not a consideration, stay at one of the 4 hotels that offers the water taxi.
They are all good for solo travelers! I like Cabana Bay a lot for the price, theming, and proximity to Volcano Bay. I like the food court there too. Sometimes I do a split stay with one of the deluxes to have express pass for a few days, then move over to CB to relax. Universal has a lot of rides with single rider lines so I get a lot done without the EP also.