The fit to throat of the chamber is where the advantage lies from increasing bullet dia., exclusive of the HP or FP which the 'spud' will put in/on it. Field .22LR chambers are often quite 'generous' and by increasing the dia. you get much the same result as using the right dia. cast bullets in a CF.
I use an old Paco Kelly re-sizer with the FP effect and it can make an otherwise indifferent grouping gun a stellar performer with 'hardware store' ammo. The FP effect seems to impart more shocking value on small game than the typical round nose (no surprise there, its the same with CF's). If you have a 'close chambered' or 'match chambered' gun you wont likely notice better groups, but of late the factory ammo has been running inconsistent larger dia. anyway and I find I can re-size and get a consistent and easier fit in loading.
I recommend the device.
BTW, the 'hammer blow' required is quite lite, but to be consistent I slip a piece of 'pipe nipple' over my die body and drop a slug of steel round stock (I experimented a bit with weight and drop). The die body/case bottom sit on a smooth, clean hardwood block. Safety glasses are encouraged and just do not be directly over the top of the unit; all common sense things. I have never had any problem, just sayin'......