First of all, at your weight and boat speed - 28 mph - definitely go with a 69". If you go shorter you will have a ton of drag. You won't be able to get much width. Everything is just going to be work for you if you get a 67". As for an Omni vs a Senate, I cannot speak from personal experience about the Senate - I'm sure its a good ski. But I ski on an Omni and I think it is a true gamechanger. I actually went from the Syndicate Pro to the Sydicate Omni. I think it is the best ski I have ever skied on. First of all, it truly is easier to get up on. Due to its design (clean edge technology and speed skin - both unique to HO) it is effortless to ski on. Where before I was beat after 6 passes, with this ski I'm ready to do double that. Its fast and turns with very little effort. Because of how little drag the ski has it is effortless to gain width at the buoy. I really can't say enough about this ski.