I'm responding to both of these with the same comment. Here are the raw stats:
https://docs.google.com/spreadsheets/d/1WnSDbSja9lar_VHZ89r_ix2mFk1KYsony2k71xtZDBc/edit#gid=0
When I had checked them last (~2 months ago) Splash had a higher painting stat than Aero, and it seems it has been adjusted slightly. The Splash still is only 1.3 less, and everything else about the weapon is superior. Faster killtime, more range, much better at combat in general, and a special that isn't only useful on 1 map.
As for Forge and Foil Squeezer, Squeezer basically has the same kit (arguably better because Splat Bombs are faster and maneuverable), the same killtime, longer range, 100% accuracy, and better painting because of the full-auto mode They both mainly play the "midrange support bubbles" role and Foil is just better in every way.
The reason I compare Eplosher and Heavy Deco. They both play the "backline bubbles" role, and have almost the same range (about 2 small inkling steps of longer range on Explosher). Explosher works better on lumpier maps, but Heavy Deco paints and kills MUCH faster on flat maps, as well as being able to better protect itself at close range.