It's a genuine Toshiba adapter, it took 2 days to arrive, and it does not over heat (so far). Only problem is that it's not the same as picture advertised. I've received the 19V 4.74A TOSHIBA PA3516E-1AC3 adapter which is also available on Amazon.
Like many others I've been a victim of fake replacement adapter, which lasted only a few of months before the transformer failed and the case split in two. I just hope that this one lasts longer.