I purchased my first 25 back in the late 80's, a Remington 700 BDL. I had grown up shooting a .243 and my pop shot the standard '06. I wanted something a bit faster and flatter so I went with the 25. It has for all practical purposes been the most accurate factory rifle I have ever had. It has only had a handfull of factory rounds through it since I got it, so I cannot say how it shoots them. With the handloads however, in any weight up to 130 it has shot sub MOA with a little adjustment of the scope out to any range I ever wanted to shoot it to. I used the 115gr Partition as a standard load and with the scope set dead on at 200yds it was simply a matter of putting the X where I wanted to hit. I have only had to shoot more than once on a couple of occasions, and these could have been arguably not needed. I head shot a skunk at 280+ yards one afternoon on a bet, and hit a yote just under the left eye at 350 from a weaving tri-pod stand one morning while wondering if the thing was still where I had left it the previous year. The load was so predictable that the duplex reticle was all I needed to determine the range of deer hogs or yotes, and adjust for the shot. My daughter now uses it with the 110gr AB's and has taken some very nice deer. The oldest grandson I think just took it over a few weeks back when he took his first buck with it.
Our first .270 came into the house when my pop retired. His co-workers asked me what to get him and I suggested it. He was totally dismayed since they all knew he shot the '06. But since we had 3 of them already I figured he MIGHT find the change of pace nice. Well it took some warming up but with a load I worked up for it, he reached out further than he would have with the '06 and rolled a big yote which was trotting across our back pasture. When he came in he said "ya know this thing will really reach out and touch something". Well he was right, but the caliber wouldn't have mattered as he was probably one of the best shots I have ever seen. That is also another one of our most accurate rifles. It has shot bullets in every configuration from 100 up to 150grs, with a little coaxing into tiny little groups. The load my mom used in it was a very mild recoiling 130gr load running just under 2800fps. It was good enough to pop sparrows off the target holder at 200yds, much to the dismay of my friend who's 22-250 wouldn't.
They are both great calibers in my mind. Do they have limitations, yes, but all calibers do to some extent. As for game size, with the bullets that have been around since the mid 80's till now, I fully believe that more has to do with who is behind them than the caliber. I would not, and did not hesitate to drag my 25 to the mountains of Colorado for elk and mule deer. I knew the rifle well and knew if I put the 115gr where it needed to be the game would stop and stop quickly. I also had the .270 along as well since it is lighter and easier to pack around I used it as well. When the time came to make the shot on my mule deer it was the 25 which was in hand and the shot took him cleanly at about 40yds, and he never took a step. I don't take questionable shots or rushed shots on game animals. If I cannot make the one I want, I am happy in the fact I had a chance.