Soon to be moving with luck!

In answer to your question, it really depends on the carrier. If you have the miles and can afford to go F then do it on the better airlines (Lufthansa, Swiss, Ana, Singapore, Thai via Bangkok.)

In my limited experience, avoid United. My flight with Lufthansa Business was far superior to United First (albeit, Old First).

Always weigh up the cost of extra cash (if doing cash + miles) - there's a big difference between 1.5x cash and 2.5x cash.

And regarding miles, figure out if you would rather have two trips in business somewhere or 1 in first (or whatever your situation is).

Would I trade 2 long-haul holidays in business for 1 in first? No. However, would I use up the remainder of my miles for a trip in First if I had no time/money for a second trip? Yes.