I haven't yet been been comfortable with the water in the boat issue. I've only tried a double blade briefly, it was a 240, which is all the outfitter had for renting; I'm willing to try a 260, but wary so far. Added that for the time I tried it, I wasn't noticing any significant improvement over my single blade.
I'm just noting as my personal experience to date, and not questioning the validity of the advantages most folks appreciate with a double.
If you are good with a single blade, the difference isn't that great. I found that out on a recent day trip with my club.
And it sounds like you aren't that experienced with a double blade, which would make the difference even less.
Having said that, I am certain that most people in a tripping canoe, having equal skill with both types of paddles, will cover ground more quickly with a double blade and find it easier to keep the canoe going straight. I can just about keep a canoe going straight, with a double blade, with my eyes closed. It becomes second nature.
Some do use a really long shaft to keep water out, but it is less efficient, kind of negating one of the benefits of the double blade. With a low angle blade, I'm generally in the 230 cm ballpark.
I've found, that, as my fitness and stroke rate increases, less and less water ends up in the boat because it is flung off the blade.
This is enhanced with smaller blade areas.
I also think that expensive paddles with foam core blades, that don't have a stiffening spine, lift less water.