Basically, yes it is good. It isn't as good as Photoshop but it's only £30. It mirrors a lot of what Photoshop does and it is compatible with many Photoshop plugins such as Silver Efex, Color Efex etc. If you're good at Photoshop, the learning curve is pretty reasonable.
Where it fails is that it does not have the same number of tutorials that Photoshop has. The knowledge base that Photoshop has is really really important; if I want to find out how to do something, It's quick in Adobe but in Affinity, it's a bigger project.
I did wonder about transitioning to Capture One and Affinity as my Photoshop requirements are modest. Adobe is a very warm comfort blanket though.