It might not feel like a true 25mm tire because of the stretch, but you'll get most of the benefits as well as the draw backs. So a 26mm may feel more like a 25mm. Drawback of any thinner tire is the increased risk of pinch flats & less corner grip. Pump up that tire to the recommended PSI or more for increased puncture resistance. Your rear may not thank you though...
I used 40PSI on my 31mm's CX tires, 70~80PSI on my 30mm hybrid bike, and 100PSI on my 25mm and 110PSI on my 23mm for the road bikes. I'm 180~200lbs though you can add or decrease some depending on your weight.
If I'm not racing I like the reliability of gatorskins ... 25mm vs 28mm.

I'm only as slow as I lead you on to believe. ; )