I've used both types of pumps. As stated above, I'm not sure either one has a price advantage when the total system cost is added up. If you do a 100% perfect install, the Tsunami will work well. If the install is just slightly off (pump a couple inches too high, etc), your bags will not fill, not empty, fill on their own, pumps will cavitate, etc, etc. Maybe it was me but I was always tweaking my aerator pumps (Like rule and tsunami). No worries with the Jabsco (or other self priming pump) since they will prime no matter where they are or what is going on. My Jabsco pumps also empty the bags 100% where there was always water left with the other system. I don't know if the Jabsco pumps are under rated or the tsunami and rule pumps are over rated but I don't find the Jabso pumps to be any slower (though they should be on paper). I fill or empty 2600lbs of ballast with 3 Jabso pumps in 10 min. One other nice plus is that you only need to do 1/2 the pluming with a reversible pump since you don't need separate fill/empty pumps.
All that said, I've spent way more time with aerator pumps so I'm very familiar with the downfalls. I had aerator pumps for last 10 years. Now that I have the self priming, I love the difference and would never go back. I don't know how long the Jabsco pumps will last but they are more $$ to replace if one went bad. It also sounds like impellers need replacement every so often (I've not owned them long enough to worry about that yet). Aerator pumps are maintenance free. My old aerator pumps were slowing down and harder to prime year after year. Not sure if it was the pumps getting old or something else was going on but fill/empty time went up a lot over the years (I used rule aerator pumps and tsunami both). I replaced an old pump and that part of the system was fast again.