25-28 feet gets small in a hurry on a big lake. Spent a few summers on a 26' Powerquest that would run just over 70mph on dead-flat water and it was waaaaay small when things started getting rougher on bigger water (Erie, Michigan, etc.). My buddy's 35 ft Fountain was a totally different animal in similar conditions. Granted, hull design plays a large role, but length will play a major factor overall. As stated above, go as large as you can afford.