I've got the iMac 5k with the system maxed out to highest specs. Faster performance in the viewport then the standard iMac as I've used both though I haven't tested with huge scenes. Of course from cinebench scores the new iMac is more powerful but that screen is said to consume some graphics power just to run. Saying all this I recently installed boot camp on my machine and cinema 4d, because I needed to use a windows plugin - shocked I must say by the increase in performance in windows compared to Mac OSX on the same machine. On the Mac I have a scene with thousand of clones and high res textures and can barely navigate the scene with textures turned on whereas it is smooth as silk on windows.
Relax sir. I work in an FX studio and no-one here would ever consider PCs. We all work on maxed out iMacs. Anyway, I will try to keep an open mind if you do. Enjoy your PC. It's just a compooter after all.
How much speed to you need? Also for a beginner a MAC really is enough for all your needs. Plus as you buy more computers you may find net render will take care of all your rendering issues. And of course the screen on an imac or mac pro laptop will kick the out of a nasty low contrast PC screen and don't forget many other professionals are using the same screens to view your work. Also add into this OSX over windows, which is designed for graphics professionals and I really do not see the advantage of a slight speed bump.
Well, here is a quick update on my progress. I started to texture und light my scene, but I'm not finished yet. A few more details are to be added as well. Though I'm quite happy with my models, I'm not with the lightning and especially with the texturing. I really have a hard time finding the right settings. The gummy-bear-material is a BIG problem, the metal of the kidney dish an the plate is too... I'm afraid, I won't be able to make them look any better. I also try to render with GI which takes alot of time. So, correct render-settings and solutions are not my thing too ... yet. Hopefully I learn to manage texturing, lightning and rendering better as in the past modeling was my primary concern... what I really hate is to have a good idea but not being able to make it look good ...
Nibuki, try using the danel shader perhaps. You can add antistrophy to the dish or noise layers etc and add an hdri to the environment channel. Fiddle with the settings - its works really well imo!