My 2 penneth – 8(ish)inch ones are better, the squarer form is better for browsing than the widescreen 7 inch ones and they’re a lot lighter than the 10inchers.
I would say, being the owner of an iPad 3, 7 inch android tablet (now sold) and an iPad mini that the mini is the best of the lot all round. I might swap it for a retina one one day, but the original is pretty damn good.
That said, I’d be tempted to try out a Note 8.0 first.