The D3300 should be skipped entirely for the D5300, as it offers far better autofocus, performance, advanced shooting features (e.g., bracketting), and better access to manual controls. Cost about $150 more.
At that range, the powershot G1x should not even be considered, its image quality is far worst along with the performance for its price range (easily outperformed by morrorless cameras at half the price.
the 70D is just not worth it unless you need its video features (which I would recommend waiting for magic lantern to come out for it first). Still image quality is still worst compared to many cheaper DSLR's, and at low ISO's there are many mirrorless cameras that perform very closely to it. (with the exception of the autofocus especially in low light)
Unless you can get the D3300 for less than $500, skip it entirely.
No Pentax Cameras made the cut when in many of the comparison tests they perform better. Plus cameras like the New K-3 are water resistant...and Pentax is one of the only manufacturers not to change the lens mounting system...so I have lenses I bought 30 years ago that work (with a few limitations) on my 2014 K-3 DSLR Camera. I also use the Pentax 645D Medium Format 44 Mega Pixel DSLR...the only really affordable Medium Format Camera on the market. So they merit a good look.