Both will do the job of getting the fertilizer where the crop can use it, regardless of rain afterwards.  I seriously doubt there's any difference in yield between one vs the other -- notwithstanding some propaganda out there.  Maybe there is, but it would take a fair number of trials to prove it adequately, and those data don't exist.

If you want to apply liquids thru a guard, you might be interested in our Valions -- they have vastly longer wear-life than TT's (which are just soft OEM guards with tubes welded on), and are easier to install, and trouble-free.  They've been discussed on this forum a number of times, so you don't have to take my word for it.