I have two 25-06's. Both are Rem 700 actions, one with a Douglas 22" 1-10" twist and the other a factory 22" 1-10" twist. The second one has over 3000 rounds through it. It's about due for a re-barrel but shooting the 110 Accubonds through it at 3200 fps and getting .5" groups I find it difficult to justify getting a new barrel for now.
The 25-06 is in it's perfect spot on deer-sized game animals on down to pasture-pests. I've taken Texas hill country whitetail out to just over 650 yards with them dropping in their tracks. I've played with it fairly often at a friends 500 yard range smacking steel with it. I took my first two elk using this rifle using 120 gr partitions. Neither was over 50 yards away when I shot them.
Are there 'better' calibers out there? Yes, most likely. That's mainly in the eyes of the shooter. If you go and compare the different calibers and cartridges strictly by the ballistics, then yes, there are some better cartridges available. Any of the off-the-shelf 6.5's would probably be a better choice for doing the same thing. Though personally, I'd go with something like a 6.5x55 Swede or a 260 Remington.
But saying that, as others stated, the quarter-bore bullets lack in BC simply because factory guns are loaded in the 1-10" twist and the higher BC bullets are too long for that twist to reliably stabilize.
If you limit yourself to 500 or so yards, the 25-06 will work well.