I would really think about what I was doing with an air gun before I bought a 30. I have one and love it in the right application. Around the house or close quarters it would not be my choice. They develop a lot of power. Far more than what I would want for around the house.
I like my 25 cal guns a lot. I have an M3 22 witha 600mm barrel that I shoot slugs out of. Due to the shorter barrel I keep the slugs on the light side, 27.5 gr.
My 25 pellet shooter is great for small game. I can shoot 25.39 out of my 22 pellet shooter but for some reason the critters hit with 25 seem harder hilt and more dead (just kidding). I do prefer the 25 for small game when using pellets.
My 25 slug gun shoots 33 gr pellets with far less effort than my 22 M3 can. Cannot put a logical finger on it but I prefer the 25 for almost everything.