Rebranding the 9 degree as a Proview was a mistake IMO. Adjusting the gain only does one thing. The fact that the 9 degree has a nice fat lobe near the transducer (ice surface) that you can utilize doesn't mean you can adjust the cone angle using the gain. The output is pretty much constant unless using LP.
The 2nd round tri beam, though better built, is morecrap imo; more noise, erratic cone shapes (blind spots) and nonintuitive gain levels when toggling between settings. It just isn't worthwhile IMO. The dual beam is sadly missed. I find I use the 12 most, followed by the 9, rarely do I bust out the 19. The 19 works great on shallow areas without weeds, but so does the 12.