Expanding on what Stinkerbell said above.
In the spreadsheet, we captured many different standard and optional featured, and compared it to "what would we buy if we purchased the current 2016 model." On almost every boat we looked at, there were things we would upgrade, and priced the cost to add those features. For example, GPS/sonar/radar, bimini, etc. In some cases, the owners had already upgraded. In other cases, owners had gone with cheaper alternatives. One thing we couldn't "upgrade" was the cab/cockpit change between the 25-classic and 25sc. It wasn't until we looked at both did we realize that the 25sc suited us better - but it could have gone the other way.
We had a number of nice surprises, and glad we didn't try to guess the features based on the year but by looking at each boat on its own merits.