@ Edvard
It depends what work you are currently doing on the PC side. There are several things that I do now, that I can't do on the Amiga:
1) Large format posters. The last one I worked on had pixel dimensions of 7k x 11k and I needed to keep it in 4 layers because one of the layers was to be adjusted by the printer after conversion to CMYK.
2) Medical models (surface and skeleton). No equivalent to the program Poser exists on Amiga. Also, I wouldn't have enough RAM to work on these models on the Amiga, and even if I did, I would probably wait until I had a grey beard before my render was finished. And I have an 060-based Amiga with a PIV, and 272mb RAM, which is reasonable spec.
3) DICOM manipulation. DICOM stands for Digital Imaging and COmmunication in Medicine. The Amiga is no longer up to date in terms of handling medical images, whereas on the PC you can get freeware to do all your DICOM manipulations.
4) Input device software. By this I mean drivers for specialised digitizing hardware such as my Epson Perfection scanner with Digital ICE filters. Not a chance you can get that on Amiga. And once again even if you did, you would be dead before you got the final image. Even on my PC, which is very good spec, it takes more than 30 minutes to scan a small photograph with an ICE filter (a special surface artefact remover for hairs and scratches and other blemishes on the item being scanned). The same applies to remote camera drivers and specialised printing software for graphics proofs.
5) DTP: if you want to submit anything useable in the publishing industry today, you best use Mac or PC.
Where the Miggy is still good:
1) Low resolution painting in Brilliance or DPaint.
2) Animation.
3) Certain functions that are now 'obsolete' or not present in modern PC software. For example I had to run several X-ray images through a resizing manipulation in ImageFX because when I did it in Photoshop the results were too good and did not give me the blockiness I wanted.
In short, if you are already using good PC software to do your designs, then using the Amiga is a step backwards. I have used my Amiga only once or twice in the last 4 years for graphics work. I miss the days when I was raytracing animations and recording those to video, though. That was fun.