The 25-06 was my main deer rifle from about 1990 until a couple of years ago when I got the 257 Weatherby (Remington Model 700CDL). Not because I was unhappy with the 25-06 - just that I had always wanted to try a 257W.
I was always afraid of a lack of penetration with the 100 gr bullets for deer so used both the 115 and 120 grain Nosler Partitions. They typically gave very fast kills as the nose would blow off doing lots of damage while the rest of the bullet punched through as designed to do.
I know many/most 25-06 guys use the 100's on deer with no problems though. Can't say I ever had a problem with them either since I never even gave them a chance.