Barrel life predictions are hard to make as there are many factors that come into play besides the basic case design. Barrel, powder, bullets, rate of fire, and so on.
Both of the cartridges you mention are not noted for long barrel life.
So if you want the performance of either, then you have to decide to forgo the "barrel life" issue and monitor your throat erosion over time.
You can't have you're cake and eat it too as they say.
My guess would be pretty close to the same but I have not shot a barrel out in either. I shoot the 6.5-06 AI, 264 Gibbs, 264 win mag and 264 STW. All four of these shoot more powder with more velocity than the two you mentioned. I have not shot a barrel out of either of mine and have shot several hundred rounds in each over the last 20+ years or so. I do not overheat my barrels at the range and keep my bores clean. If you do that either of the ones you choose should last you plenty long enough to make the investment worthwhile.
Predictions are difficult, especially when they involve the future
6.5-06 would be easier on the barrel than say a 25-06. It's a powder amount ratio to the bore size. I sold my 30-378 when it was needing it's third barrel. But a day at the range I can go through 200 rounds. 30-378 have bad erosion in just 400 some rounds. I have 277 cal on their second and third barrel but that is thousands upon thousand of rounds. Like in three days of P-Dog hunting I shot @ 1000 rounds out of 4 rifles. Or when I was in the military sniper school. 5 of us shot 8000 .308 rounds in one day.
.270 Ackley improved 29 inch 1.250 dia. target barrel 7mm STW 28 inch 1.250 target barrel. I also love my .458 mag for varmints and the biggest game in the world.