Both iPad 3 and 4 had 1GB RAM. The problem with the iPad 3 is insufficient GPU.
Haha realized that when i went to check right after posting. Basically the 6s fixed the constant reloading due to lack or ram to support the higher res and the 4 addressed the lack of gpu power basically the 4 was a ipad3s.
And this is i guess always the concern people have when purchasing tech products but its inevitable.