The "perfect" tablet is subjective, since everyone's wants and needs are different, but that won't stop us from discussing the subtle -- but impactful -- changes that show how tablets are evolving toward a design apex.
Tablet manufacturers have taken some tips from Goldilock's playbook, trying out different sizes until finding the optimal one. Even now, multiple form factors are expected from any line of tablets, with 8- to 9-inch tablets being the latest trend. With the variety of sizes available today, you can probably find a slate that perfectly fits your hands -- and needs, of course.
Tablets used to pack plenty of ports, but now you're lucky if you get more than one. Lack of ports hinder the possible functionality of your slate, but if you're a casual user, you won't notice the difference.
For most tablets, a power button and volume rocker suffice, but this hasn't stopped manufacturers from fudging it up. RIM and Amazon once offered slates with embarrassing button functionality -- or lack-thereof -- but have since discontinued those models.
Not all manufacturers have learned a lesson in functional-button-minimalism; Samsung Galaxy Tabs pack capacitive buttons that are sometimes frustratingly easy to trigger. When it comes to buttons on tablets, less is more.