Looks promising..............but I still have the bad taste in my mouth over Pixelmator. Same high praise, same capabilities, affordable, and was touted as the program that was going to replace Photoshop. Again very promising but any realistic support only lasted about a year or so and the program went downhill fast. The development team made ridiculous changes trying to keep up with the Jone's, and it became known as a crash king. Some people still defend it but it's a dawg.
I would not invest in Affinity Photo just yet, give it some time to see how it does.
I've tested Affinity Photo for several days on iMac. It's hard to jump from PS, when you are so used to it on daily basis, but as far as I tested:
Runs much, much, much faster which is actually nice benefit.
You can save your history within a file so you can reopen file after year and do some undos with (fast working) slider.
Most of the shortcuts appear to be exactly the same ones as in PS.
It opens my old psd's with no problem
It has many nice features, some of us will use them others may doesn't need them.
The thing I noticed which is a giant problem for me:
Complete lack of Smart Object or any substitute (opening PSD with smart object will flatten SO into plain pixel layer)