Having done both with a variety of calibers I can +1 on the OK for low-mid pressure loads, and for specifically reduced velo, cast bullet loads, though the neck dia. is sized down far enough to tightly hold the nominal jacketed bullet dia. for caliber which is not the optimum for lead bullets. The cost of many Lee Loader sets are now so close to a basic 30-40 conventional dieset that I really recommend 'biting the bullet' and getting set up such. The Lee Handpress has worked well enough for me that I now have two (as well as a turret press and a Rockchucker), they are just 'handi' too. It is nice to batch some cases while in my livingroom with a good movie and my wife & dog (yes, in that order...) rather than down in the mancave.
Now if you have a 30-40 hand pounder and want to try it out first, go right ahead. My guess is that some not too distant point you will want/need to FLS some of your cases and then what to do? If you have to buy one you will still get to that point and it might start to look like you would have been money ahead to have gone the whole hog.
So, if you want to load the 30-40 to its potential you will need a dieset, if not you may as well keep it at 30-30 and not top loads either.