SreckoM
If you want to stay with OSX than you already answered your own question. Just you have to prepare yourself for wait. Some developers will support Metal directly some will not. No one can give you exact date. Prepare for wait and uncertainty. That is going to be long process (stretched over several years). I had same doubt when trashcan was out, and back than decided to switch to Win/Linux and it proved to be right move. It had great GPUs back than but it was outperformed by 2x cheaper Nvidia cards pretty quickly. Only one render engine was using their full power, and when that engine arrived those card were already outdated. I do not consider switching back to OSX anymore.
If you want to squeeze most $ from your investment, want it right away, PCs are, especially with new Ryzen CPUs, better choice.
All this is related to 3D and Houdini, if you want talk about broadcast industry than you are on wrong forum.
Not sure where anyone was talking about broadcast industry to make you say that, but at least you made some points about why you like PC. That said, it's still an opinion and “better choice” is relative.
Mac is the better choice in my opinion and I believe Metal 2 is the future and going to be the platform to beat in the next several years. But that's just my opinion and I'm not here to try and change your minds, I really don't care what platform you use, and believe you should use what best makes sense to you as an individual artist, not what anyone says on a forum.