As others have alluded to, if you're always flying business class for work then perhaps it's not worth it for you. But since you asked, I'll give my perspective.
This year is the first year I've hit 1K (last 2 years I was plat). I've found the bump to 1K to be very very valuable for the way I travel. I travel internationally often, far more than domestic, and my company has a deal that if I fly in economy for an international trip they give me a stipend for the inconvenience (which at the end of the day is a lot less money than if i just bought business class). My company also does not monitor the fare type, so long as it is in economy. Almost all business trips I purchase B fares for the PQM accelerator, lack of co-pay for upgrades, and higher chance of being upgraded.
So far this year, I am 12/12 on international upgrades and I also got CPU'd a few times domestically. I use the 6 GPUs to upgrade my 1st 6 flights in the year and i end up accumulating a ton of miles (over 250,000 this year). When the GPUs run out I upgrade with miles (which do add up quickly but I bank a lot early in the year). By the time I am running low on miles, boom I've hit 1K again and the GPUs are redeposited. This is where I am now at 121k PQM. I'll get 2 more RPUs soon and in the future 2 more GPUs.
So, for me, being 1K has completely changed my flight strategy.
But, as I said... if you're just buying business outright it probably doesn't matter much! My 2 cents
