Let me preface this by saying that I do not have any experience with the .257 115g. VLD's impacting game and their performance. I do have some experience with the Barnes TSX's tho, and a couple of other bullets as well on whitetails and a couple other critters.
I have shot a Northern Wi. whitetail doe in the lungs with a .257 Nosler BT with a very similar MV @ 80 Yds. She ran just shy of 100 Yds before piling up. There was a couple of inches of snow on the ground, so tracking was easy, plus I could see her when she dropped. The bullet entered, but didn't exit. It shattered one rib on the way in, and pulverized the lungs. While the bullet did it's job, there was no blood trail until about 10 Yds before she dropped. I really didn't like that, so I switched to the Barnes 100g TSX's. I found an accurate load with them trotting along in the high 3700 fps range, and have taken Northern Whitetails from 50 Yds to just shy of 200 Yds, and a Corsican Ram @ less than 20 Yds. Every shot has exited, and the animals haven't taken more than a few steps, if any. The Ram was dead on the ground before the hair that the bullet cut made it to the grass.
I loaded some 130 gr. Wildcat bullets for a Wyoming hunt this year, and the MV on those are 3250 fps. I shot a Mule Deer buck @ 48 Yds (3170 fps impact), and a Pronghorn @ 323 Yds (2750 fps impact) with them and both exit wounds looked identical, even tho the Mulie buck had his spine shot and the Pronghorn had the top of his heart removed (both were broadside shots). The bullet exited in both cases, albet in pieces, but it did exit. The mulie dropped where he stood, and the pronghorn took a few steps first.
I know that this might not be much help, but that was my experiences with .25 cal bullets. If I was in your shoes, I would try and shoot one shot into a couple of wet phone books at close range to see what the VLD will do. While I have them loaded up for the Vanguard, I would be hesitant to take a close shot before seeing what they would do at a high impact velocity. I didn't plan on shooting the .25 cal 130g Wildcat that close, but with 10 minutes left in the hunt, you take what's given to you!
I have faith in the Barnes TSX at close range, but the bc isn't good enough for me for any distance work. Personally, I try to figure on 900 fpe at impact as a minimum for whitetails.