I used to load exclusively flat based bullets in my .308 when I first started loading as I was (wisely) advised to use the specific component set tested in my Lyman loading manual. This practice served me well for many years until I drank the Kool Aid. Believing there was something to be gained by switching to a boat tail design, I tried some out. I found them generally less accurate (with a few exceptions) in my particular rifle and others. I could get them to shoot well, but they required significantly more load development to find their happy place. With a flat based cup and core, the book max load and COL generally got me acceptable accuracy. With boat tails, this was sometimes true, but often not. With the Hornady SST, this was generally true (see .308 penetration thread for additional information of my experience with those).
Fast forward some 35 years from my first rifle cartridges, 100 or more deer shot by myself, wife and friends, and I think I can draw some meaningful conclusions. I've loaded BT: Sierra BTSP, Nosler Solid base, Hornady SST, and Speer BTSP. Flat base: Speer Hotcor and Mag Tip, Speer GS, Hornady IL, Rem Core Lokt. I've found performance of the FB bullets on Northwoods deer to be superior. They just hold together better. The BTs kill deer, but the few failures I've had at moderate velocity primarily in .308 and .300 Sav have been with BT designs, and a hit near edible parts results in additional meat loss. The exception was the old Nosler Solid base. I dearly miss those. I found there performance indistinguishable from the Hornady IL. If you run the numbers, the Speer Hot Core in medium for caliber weights especially doesn't give up much in the way of BC to similar weight BTs. The Hornady IL isn't far behind. I don't think one would notice the difference to 300 yards.
I now shoot exclusively FB designs for hunting with the exception of one dedicated LR load in the .280 Rem and various practice ammo using up old stock or sale/shortage items I've acquired over the years. I subscribe to the pass through theory in terms of deer hunting, and just believe the FB designs, especially the Horn. IL and Spr HC perform this task more reliably.
My match ammo is loaded with BT designs as I'm shooting to 600 yards where the difference is notable in terms of wind drift, and I pay the price in terms of extra load development to get them to shoot well.