I think there is a middle ground here. At least SOME of your practice should be done with load similar in terms of recoil and muzzle blast as your carry ammunition, particularly if you carry a very "hot" ammunition (e.g., full load 125 grain .357 magnum JHPs) and practice with low intensity (e.g., 148 grain .38 special wadcutters). For the most part, shoot what ever is cheapest--marksmanship is a mechanical skill that requires practice, but if there is a great deal of difference between your practice loads and your carry loads, you probably should fire a couple of magazines/cylinders of your carry load or a similar practice load. (I usually solve this by shooting my currently loaded carry ammunition--the stuff that has been in magazines/cylinders for a while. I believe in rotating my carry ammunition frequently even though it can be expensive (admittedly, I do not have high capacity mags so I don't have to take out a second mortgage to refill my magazines).
The need is less for practice than to be prepared for difference if the need arises. For example, my carry load in my CCO is ProLoad 200 grain +P--it feels and sounds different than the generic 230 grain ball I with which I do most of my shooting--when I was carrying ProLoad's 230 grain +P the difference was far more pronounced. The same hold true only moreso if you carry one of the small .357 magnums and only practice with low intensity .38 specials. If you chose to carry one of these beasts loaded with 110 grain or 125 grain .357 JHPs practice some with your carry load and try to fire some later in the evening (where you can see the muzzle flash). I really cannot recommend it, but you might want to try one or two rounds without hearing protection. If you ever have to use a handgun for self-defence, the odds are it will be dark, and you will not have hearing protection. It might be nice to know what to expect (particularly if you have to do any follow-ups).