I for one love Perfect Effects. I am currently using latest version On1 10. My go to effect is Dynamic Contrast. It can really make landscapes pop.
An example would be this image. Processed in Lightroom CC, tweaked in PS CC015 with Nik Dfine2 noise reduction & Perfect Effects Dynamic Contrast.
I also use their B&W conversion filters, Prior to version 10 they were in the Perfect B&W module of teh Photo Suite. In version, they are option within the Effects module, This image was first processed in full colour in Lightroom, Perfect Effect Dynamic Contrast was applied in Photoshop and save. Then in Photoshop used Perfect B&W to convert to B&W and saved as a separate image.